Item No: NKB200272S

Price:   $649.00



These heads have have steam holes for sbc 400 or 406 engines.


This auction is for one fully assembled set of heads.

The springs in this setup are to operate with hydraulic flat tappet cams up to .550 lift. For those runing hyd. roller cams, see our other listings for these heads with the part number NKB-200-274-SH


The pictures above are of our former Procomp heads. We will have updated the pictures very soon. The new NKB-200 heads are actually a much better looking head. 

These heads have a full set of steam holes in them. The holes are drilled at the proper angles, and the correct location. If you don t need the heads with steam holes, see our other listings. 

Our custom built NKB-200 aluminum heads with 200cc runners, 2.02/1.60 stainless valves, 1.46 diameter dual roller springs. These heads are not built by Procomp, and have no association with them in any way. 

We have complete hardware kit available for the NKB-200 heads with steam holes in our other listings. The kit has the correct head and intake gaskets, head bolts with special washers, and stainless intake bolts. The part number is TEK-1014-1205 

A breakdown of the part number.

 The NKB stands for, "New Kid on the Block", 200 number represents the runner size, 272 designates the use of 100 long valves, and single springs with a damper setup for hyd. flat tappet cams. You will also see the heads listed with the number 274. The 274 designates the use of 200 long valves with dual springs with a damper, setup for hyd. roller cams. We also have the valve train setup for solid roller cams, and will have the number 583 rather than 272 or 274. The heads listed with the letter "A" in the part number are angle plug design. The straight plug version has no designation. The steam hole version is only available in straight plug. These will have the letters SH, (Steam Holes) in the part number.  Be absolutely certain of what you need before buying. Feel free to call us if you need assistance deciding what you need for your build. 423-722-5152


The springs in this setup are to operate with hydraulic flat tappet cams up to .550 lift. For those runing hyd. roller cams, see our other listings for these heads with the part number NKB-200-274-SH

200CC runner size, 64cc combustion chambers. 2.02 1.60 valve size. Fully assembled with premium hardware. See our other listings for these heads with our new extreme duty PBM valves. 

Our new NKB-200 heads have been designed especially for us. With many recommendations from our engine builders as to how the heads should be, we have came up with the best quality, best flowing heads on the market relative to cost. The only way your going to get a set of heads that flow as good or better will be to spend at least double the cost or more. We have installed these heads on all of our 383 and most of our 406 engines for the past 3 months. Many of these engines were dynoed on our new Superflo dyno. The engines had every possible combination of cam, intake and carb. The results have been amazing. These heads are excellent in design and quality. Our choice of hardware and precision assembly also contribute to the performance and reliability of the heads to a great extent.

These heads can be used with outer perimeter or center bolt valve covers.

Flow chart information.

Below is our flowchart on several different heads. All test were performed on a Superflo 1020 bench by our expert head builder. We stand behind the accuracy. We have noticed many other sellers posting what we consider false flow numbers on the heads they are selling. We find this to be nothing short of outright fraud. Sure flow numbers can vary a few points depending on equipment used, and testing methods, but not 15-25 points. Thake notice to the low lift flow numbers produced by our new heads. That is as important as the upper lift numbers, and why these heads produce so much peak power and torque. We are very impressed with the flow numbers of our new heads.

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Take notice of the flowchart above. The NKB-200 are superior to the Procomp heads in flow numbers, and also edge out the Dart SHP heads on the intake side. The intake numbers are far more important than the exhaust. The overall average flow numbers on the NKB-200 heads are higher than most any brand of non cnc d cast aluminum heads on the market. We guarantee the flow numbers to be accurate, as well as the horse power numbers produced by them. Whats most important about the flowchart above is the fact that all three of these heads were tested by the same person, on the same machine, (Superflo bench 1020) same testing method, on the same day. Regardless if the numbers are absolutely correct by other standards, they show the true difference between each other, and that s what counts. The difference in horse power, and torque generated by these new heads is monumental compared to the Procomp heads. We offer four different cam choices with our 383 and 406 engines, and every combination has showed an increase of up to 50 horse power and no less than 40 hp when coupled with the various combos. We assumed the new heads would make a considerable increase in power from what we seen on the flowchart, but to our surprise they made much more power. We tore down the heads that were on our 383 house engine and checked the guides as this was an area we are more concerned about then any other aspect of the head, and found zero wear. The seats were also in perfect condition. We tested the spring pressure to see how much was lost after a brutal 80 or so dyno passes, and seen approx. 10 lbs of pressure drop on the nose, and even less on the seat, and this is to be expected. Many of the dyno passes were ran to 6500 rpm as the large cam needed 6300-6400 rpm to make peak power, and you must run a couple hundred rpm past this to determine where the fall off is. The super sized cam, (choice 1) was ran on the heads towards the end. Considering the size of this cam it was very impressive to see no issues with the heads or hardware. We made a good 25 passes with the big cam trying out different carb sizes, jetting, intake manifolds, timing setting, and adding the Super Sucker plate last. As of, 11/23/2013 we will be removing our house engine from the dyno and putting the engine in a test vehicle. The objective of this will be to test drivability on different combinations, and to further put the engine under high usage. Considering several of our engine builders commute over 70 miles per day round trip to work, putting mileage on our engine will not be a problem. One more thing to consider, these heads are making this huge increase in power compared to our former heads, with 10cc s less runner size. Anyone can put a set of hogged out over sized heads on an engine and make horsepower, but at the cost of bottom and mid range power, as well as throttle response.

The hardware setup is for use with hydraulic flat tappet camshafts up to .550 lift. See our other listings for hardware setups to accommodate hyd. roller as well as solid roller cams.

If your not sure about the type cam you have or soon to have, please give our tech support a call at 423-722-5152

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The warranty will cover the castings, seats, and all hardware.

Important note from Skip White" 

 We certainly know where to draw the line with low end products, and continue drawing that line with the elimination of parts that we once accepted but have shown to be a potential problem sooner or later. Sometimes it s not that a particular product has or will have a problem, but something better comes along. To be honest this is that, "something better" coming along. Considering the price is only slightly higher, this has to be the best value in a set of cylinder heads we have ever offered. We now use the NKB heads on all of our 350,383, and 406 engines. The performance has been outstanding on every combination we have tried them on. I want you to take my word that in the rare event you have issues with our NKB-200 heads, the problem will be taken care of.

Skip White    

 As our company founder explains it, the results of these heads will vary greatly by what type setup you are running. Our engine combos we have dynoed are what most people have chose to use as far as cam and intake selection goes, and we have the results listed below. The engines dynoed were many 383 s, and several 406 cid engines in the 10:1 to 11.2:1 compression range, give or take. All ran on pump gas. Our Stage 2.2 383 engine add has a selection of four different cams. I have copied this info from that add. This will give you an idea on what these heads are capable of with a given combination of cam, intake, rockers, and carb. This may also help you select a proper cam for your build. As mentioned, below is just an excerpt from our Stage 2.2 engine add. We have also built, and dynoed a 350 engine recently with the new NKB-200 heads for a customer, and will have the actual dyno results in this add soon. The cams mentioned below are all hyd. roller cams. If you using a lower lift from those listed below then it would be fair to say the hp will drop, but not by much providing your lift and duration are somewhat close to any of the cams mentioned below. This will give you an idea of what kind of power to expect with these heads, and it can certainly help you choose a cam and intake. Please do understand that a cam is not included with the heads. This is just a guide to show what you may expect with a given combination when building a 383 engine. 


Cam choice #1

PART # 186755-10 This is a hyd. roller cam for use with oe roller blocks only.

PART # 116755-10 This is a retro style hyd. roller cam for use with non roller blocks.

  • VALVE LIFT WITH 1.5 ROCKERS : INT .600 / EXT .580
  • DURATION @0.050" : INT .251 / EXT .255

This cam choice # 1 is very aggressive in the 383 Super Stroker engine. We have not offered this cam in the past with any of our 383 engines. This is the same cam choice 1 used in our 421/427 engines. The reason we decided to try it was to see what the max potential was with our new KNB-200 cylinder heads. We pumped up the compression a bit with a flat top set of pistons, topped it off with a set of 1.6 rockers, and went with the Single plane Hurricane Plus intake, added the Super Sucker plate, and produced an amazing 552 horse power at 6400 rpm with 502 lb ft of torque at 5400 rpm. Actually the engine produced only 4 hp less at 6300. Very good these numbers are for not having to run the rpm any higher than this. The horse power numbers are very accurate. We preformed the testing on our new Super Flo 902s dyno. No question the numbers are correct, as we have been spot on with all of our other dyno tests of engine combos that we knew what to expect from past dyno records. The flowchart for these heads is below, and certainly explains why we achieved such numbers. This setup is considered pure Pro street, and only usable in very light weight cars with proper gearing, and a stall of 3200-3500. This is due to the cam size, 1.6 rockers, and intake choice. The compression ratio is right at 11.2:1 and can not be ran in very heavy vehicles with tall gearing. The drivability as it s referred to would be considered poor with this setup in a medium weight vehicle, (3200-3500 lbs.) Nonetheless it is your option to select this setup but do realize that gearing and stall are critical even more critical in a medium weight car. Those not familiar with Pro street setups will should educate themselves on the subject before choosing. Those sporting about wanting street manners, explosive power off the line without the need for deep gearing, and the need for a high rpm stall converter, need to stay away from this setup. Below are three more choices that will better suit your needs. On the flip side of what was just said, those that want the most powerful pump gas 383 available, and enjoy the thrill of a pro street setup need look no further. This setup would please the Pro street minded to a very high degree. This cam beats the ground with no mercy. Give it the right stall, gearing, and a set of ET streets, and you will have that sound and feel of power with acceleration unlike any 383 has every achieved on pump gas considering the cost. For those wanting a bit more power and not sacrifice any more drivability, then I recommend going to our 406 cid Stage 3 or 3.5 engine with the same setup. The 406 engine will move the torque band down much lower in the rpm range.


Cam choice #2 

PART # 180345-10 This is a hyd. roller cam for use with oe roller blocks.

PART # 110345-10 This is a retro hyd. roller cam for use with non roller blocks.

  • VALVE LIFT WITH 1.5 ROCKERS : INT .565 / EXT .580
  • DURATION @0.050" : INT .245 / EXT .253

This cam choice (2) coupled with our single plane intake with our -8.5cc reverse dome dished forged pistons will produce right at 510 horsepower at 6,200 rpm. Compression ratio will be right at 10.4:1  It must be noted that the dual plane intake will have much better drivability, and throttle response is also noticeably improved. The engine would feel stronger with the dual plane intake in the bottom and mid range. The single plane intake would have a greater impact on the hp numbers if the engine was setup in race form, as we have seen up to 20hp difference on larger cubic inch engines, and/or higher compression setups with larger heads and cam. The single plane intake is not recommended for use in vehicles weighing over 3250lbs. The rockers used on our test engine were the Comp 1.6 High Energy aluminum series. Our cam timing components were left in the straight up position. Ignition timing was set at 33 degrees total. 93 octane fuel.  During very hot weather, total timing should be set at 31-32 degrees. This cam choice should only be used in vehicles weighing around 3,400 or less, and final gearing and stall are to be in the slightly aggressive zone. A final gear of approx. 373 and a stall of approx. 2,800-3,200 would be suitable.  


Cam choice #3

PART # 180265-10 This is a hyd. roller cam for use in oe roller blocks. 

PART # 110265-10  This is a retro hyd. roller cam for use in non-roller blocks.

  • VALVE LIFT WITH 1.5 ROCKERS : INT .530 / EXT .545
  • DURATION @0.050" : INT .233 / EXT .241

This cam choice (3) is the perfect all around setup for those wanting a decent bottom and mid range, yet still making excellent power at the top. This engine will use the same pistons as the cam choice above, but your could have a bit less compression ratio and that would be fine in a 383 engine. Horsepower rating would drop to approx 465 with this cam. This cam will make it s peak power at approx. 5700 rpm. If your car is in the medium weight range or up to approx. 3,700 lbs, and your wanting slightly better streetability, then this is a good cam choice. You still want to keep the final gear ratio at .323 or numerically higher, but keeping the gear ratio on the tall side is more acceptable with this cam compared to the other choices mentioned above. You may choose 1.5 or 1.6 rockers with this cam, but we recommend the 1.5 rockers for better low end response. This cam should be paired up with the dual plane Crosswind intake for better drivability. The single plane Hurricane can be used, but the dual plane will have much better bottom end and mid range response. You can also expect a longer valve train life with this cam compared to the larger cam choice # 1 or 2 


Cam choice #4

PART # 180245-10 This is a roller cam for use in oe roller blocks.

PART # 110245-10 This is a retro style roller cam for use in non-roller blocks.

  • VALVE LIFT WITH 1.5 ROCKERS : INT .500 / EXT .510
  • DURATION @0.050" : INT .225 / EXT .231

 This cam choice (4) has a slightly lower lift and duration than the other two offered above, and is highly recommended for use in heavy vehicles or full size sport trucks or very heavy cars. The low end response with this cam is very good. Horsepower rating would be approx 440-445 at 5,500 rpm. Compression ratio in a 383 could be as low as approx. 9.6:1 with this cam. Slightly higher would be recommended in a 350 build. The rule of thumb with cam size is that the smaller the cam is in a given application, it will always improve low end response. One more benefit to the smaller cam is that the requirements for lower gearing and higher rpm stall converters is reduced. A final gear ratio of 310 would be acceptable with this cam. The bottom end power would be much better with this cam than the two other choices above. This would be the only choice for those wanting to run an overdrive transmission such as the 700R4 and be able to cruise at around 2000 rpm in overdrive. A stall converter of 2,200 would be the minimum for this cam. Do not choose the single plane Hurricane intake with this cam, as it would be totally impractical. Valve train life is extended greatly with this cam as compared to the other choices listed above, drivability is at it s best. Low and mid throttle response is very strong. This cam choice will also produce the greatest amount of vacuum at idle as compared to those listed above. If you need help in selecting a cam to suit your needs feel free to contact our tech. department at 423-722-5152 


We have had a few customers wanting to run their engine in a very heavy vehicle such as a 3/4 ton or 1 ton dually, 4x4 quad cab truck, or Chevy Suburban. These vehicles weigh approx. 6000 lbs or more. Even if you don t plan to do any towing or hauling heavy items, none of the three cams listed would be suitable for this. We do have cams for such applications. We have recently did a dyno run with a cam that would be ideal for such vehicles, Howards part number, 180315-10. Compression ratio could be as low as approx. 9.3:1 with this cam in a 383 build. This particular cam made 425 horse power at 5300 rpm and produced 458 lb. feet of torque at 3500 rpm. This cam would be perfect in very heavy cars or trucks. Stock gearing would be possible and reliability would exceptional. We would consider this engine a true Torque Monster.

An expert from our engine add about our new dyno. 

As of 9/15/2013 we have completed installation of our brand new Super Flow 902S dyno. In the past we have out sourced our dyno work. Never being able to do the research and development we truly wanted, prompted us to make the $105,000.00 investment. Needless to say it s been the best investment we have ever made. Every aspect of our engines can now be monitored, calibrated, tuned, and best of all see what combos make the best power, with consideration to drivability. One thing we have noticed is that the de-tuned engines with different cam and intake combos certainly do have less top end horse power as expected but the torque increase in the low rpm range is much greater than the higher horse power setup. This increase in torque down low is what you want if your sporting around on the street, rather than all out racing. The de-tuned version of this engine will also allow you to set the car up closer to stock and increase drivability to a very high degree. Throttle response is also noticeably better. We have also built an engine that we refer to as our "house engine" Every week we put this engine on our dyno to do our research on different combos of cam, intake, carb, as well as changing settings to optimize the engine. The NKB-200 have ran over 80 passes on this particular engine without fault. What we are also doing is putting this engine through a durability test to see how the parts are holding up to extensive dyno testing. We have tore the engine down once already after approx. 80 hard dyno passes and found zero wear or failures of any of the parts used. We tested cylinder leak down compression, bearings valve guides, and many other parts in the engine. We even tested our spring pressures to see how well they are holding up. We put the "house" engine back together and will continue testing. Our objective is to build our engines as reliable as possible.

We do not include studs or guide plates with these heads. Some sellers may include these items, usually of a very low quality. Please read the information below on our recommendations on rocker arm studs, and guide plates. We have lowered the price to compensate for the fact that these items are not included.

Rocker Stud recommendation:

 We insist on the use of ARP rocker arm studs. No other substitutes will do, with the exception of the GM Performance brand. We have seen several very serious design flaws on the import rocker arm studs that are on the market. This was not a problem several years ago, but it certainly is now. We no longer offer the lower cost rocker arm studs and never will again. The additional cost for genuine ARP studs is very little considering what problems the low quality studs may cause. The problems are serious enough we can not warranty the heads unless the correct studs are used. There are several items that we take no chances on regardless of how appealing the price is, and the import rocker arm studs are at the top of the list. As for other sellers offering studs and guide plates with their heads, it would be a fair assumption they are using the low grade studs. We have a detailed explanation of how important a high quality rocker arm stud is at the bottom of this listing, PLEASE READ IT! See our other listings for valve train related items that you may need for your project.  The part number for the correct studs and guide plates to be used with these heads is 38-GP for those running 3/8 s size roller rockers, and for those with 7/16 s roller rockers the part number is 716-GP These kits are available in our other listings.

Head bolt washer recommendation:

The NKB-200 heads require the use of special head bolt washers, and extended reach head bolts. Using stock length head bolts will not allow the use of the special washers required, as the oe bolts have a limited amount of thread on them. Not using the special head bolts and washers may cause serious damage to the cylinder heads. The problems associated with not using the special washers has no doubt been a source of serious damage to the casting on these and many other brands of aluminum heads. See our other listings for many of the items needed to complete your engine build. The correct part number for the head bolts to be used with these heads is 2451-W or ARP-134-3601 If you purchase the top end kit we offer for these heads, the 2451-W head bolts are included.

Guide plate recommendation:

We strongly recommend the use of the Dart guide plates with these heads, or any aluminum heads for that matter. These type of guide plates will allow better rocker tip alignment due the fact the rocker stud holes in them are oval shaped. We use them on every set of heads we install on our engines, including the Dart Platinum Pro-1 s. For various reasons the rocker tip may end up offset to one side more than is acceptable, and the Dart guide plates will allow a decent amount of correction. The variances in stud position to valve guide alignment vary on all brands of heads. The rockers could also contribute to this issue, as the trunnion or rocker body could have variance. By having proper rocker tip alignment, you are distributing the pressure on the valve tip evenly. This not only reduces uneven valve tip wear, but too much rocker tip misalignment on the valve stem can create undue stress on the valve guides in the heads. See our other listings for many of the valve train products that you may need for your project. The part number for the correct studs and guide plates to be used with these heads is 38-GP for those running 3/8 s size roller rockers, and for those with 7/16 s roller rockers the part number is 716-GP These kits are available in our other listings.

Pushrod Recommendation.

It is highly recommended that you do not use stock GM pushrods with these heads. The spring pressures on aftermarket heads is somewhat higher than oe heads. Combine this with the larger lift and duration cams often used, and stock pushrods will surely flex or possibly permanently bend. The stock pushrods are usually made from a mild 1810 steel that has been heat treated. Under high rpm they will usually flex and cause a loss of lift resulting in a power loss. The engine will usually run with an erratic nature when pushrods are flexing. The Spintron valve train dyno proves that inadequate pushrods will flex to a great degree as engine rpm increases. Some GM pushrods have a welded ball on them, and they stand a great chance of breaking off with the use of larger than stock cams, and increased spring pressure. We offer pushrods made from 4310 chromolly with an .080 wall thickness. They are superior to any stock pushrod. Our prices on them are the best you will find. The size that you will most likely need with the NKB heads will be 7.800 This size has worked well for us when using the Comp high energy rockers, but we did notice that when using the Scorpion rockers a 7.900 was better suited. There are many low cost pushrods on the market in the $29.00-$39.00 range. These low cost pushrods are totally unsuitable for use with these heads for the many reasons mentioned above. One more reason not to use them is that they are not guide plate compatible. They usually have a wall thickness of only .065 . Rest assured these type of pushrods will cause problems when used on a high performance setup. There are many factors that can determine pushrod length requirements. The 7.800 length is the most applicable. Should you purchase a set of pushrods from us, and find that the length is not suitable, you may return them, and we will send out the size you request.

The video clip here is of our company street rod with the Stage 1 350 engine. This engine had the Procomp heads on it. The NKB-200 heads would have made a considerable difference. We will have an engine in the car soon setup with our new heads on it. 

These heads used on a 350 engine build will produce approx. 350-435 hp. on pump gas depending on cam, intake, rocker ratio, and carb. When combined with a 383 stroker engine, the horse power and torque numbers increase dramatically. We have achieved 550 hp in our Stage 2.2 383 Super Stroker engine, setup up for street use, and able to run premium pump gas. 

We have thoroughly tested the NKB-200 heads on our Superflo 902s Dyno. The results have been amazing with each and every cam combo possible.   

  Most sellers do no testing whatsoever on the cylinder heads they sell. We do more than just flow testing before we market a new style cylinder head. We made over 80 dyno passes with these heads, and we found them to be up there with the best on the market. 

As mentioned we made at least 80 dyno pulls with the NKB heads, and they performed faultless. Cam, carb, and ignition testing is what led to so much testing, but also an opportunity to make sure the new heads would not have any reliability issues whatsoever. Our head builder made special note about the excellent style of cutting on the seats in these heads. Our engine builder told us that our line of intake manifolds mounted decently on the heads, and the heads mounted perfectly onto the block. We asked them to make special note on this. All in all, they are very well made in every aspect. 

One of the worst mistakes you can make building up an engine is to get a mismatched combination of parts. We know about combinations and how they work. Take a test drive in a car with over 400hp vs. a 300hp or less and you will then see what you’re missing. The exhaust sound under load is very pleasing. These heads will make the power you need without spending a fortune. We are very pleased with everything about them. We are often asked to compete with others selling at lower prices, yet consideration for the quality of hardware used is not given, not to mention the way others may be setting up the heads could cause serious problems to the heads or the cam. Few if any of the others know much about the correct way to setup a set of cylinder heads.  

Our Stage 2, 2.2, 3.0 engines are all now built using these heads. We do offer the Dart heads as an upgrade for these engines, but the increase in price is considerably higher. Read the full story on how these heads performed on our 383 Super Stroker pump gas engine. See our Stage 2.2 engine add. 

 Our choice of hardware also makes these heads stand out compared to others. Our testing has been very thorough on these cylinder heads. As far as we know none of our competitors do this. We hope you can value this. We do know for a fact that many dealers are using substandard hardware regardless to what they may say they use, and do not have a true head builder doing the assembly, not to mention the very expensive equipment we have at our shop. Please check out our listing on valve springs, and this will give you an idea of how serious we are when it comes to valve train hardware. Beware of sellers that offer little or no information on the hardware they use. 

Our Stage 2.2 383 dyno results with the NKB-200 heads: To be listed very soon. 

The video clip below were made some time ago. The engine was our 406 engine with the Procomp heads. It would be fair to say that the NKB-200 heads would have given the engine an approx. 50 hp gain for sure. 


Here is a rundown on the hardware we are using

NON MAGNETIC stainless steel valves, swirl finished one piece undercut. The same valve we have used for years. Non magnetic is very important. Our cost on these valves is around double the price of some low cost valves on the market. We know for a fact that many head builders use the low cost magnetic valves. We do not use them and never will. If the valves pull a magnet, they are not high temp stainless. They may be stainless, but they have very low nickel content in them. Stick a magnet to your stainless kitchen utensils; it will pull a magnet very strongly. Kitchen utensils are made from 400 series stainless, and have very little nickel in them, as they don t encounter extreme temp ranges. It is the higher nickel content that allows a valve to withstand high temperatures.

Our springs are 1.46 diameters, with an internal damper. Others are using springs that are much smaller in diameter. Smaller diameter springs may be in the correct spring pressure zone, but they are usually very short lived. For those running other style cams, see our other listings for heads built for these type cams. We have also seen spring kits on the market that are larger in diameter, but are made with much thinner coil material.

We use only Comp Super 10 degree machined locks. Our head builder found most other locks on the market to fit looser than he felt they should be. He envisioned the engine being much more prone to dropping a valve at high rpm with many of the other no name locks on the market.

We hone every guide in the heads with a ball berry flex hone to establish not only perfect clearance, but also a semi cross hatch finish for oil retention. We finish off with a natural bristle brush. The heads are then placed in our parts washer and cleaned with high pressure hot water then pressure dried. This procedure is not performed at the factory due to the fact some engine/head builders prefer to establish the valve to guide clearance and finish in different ranges. We feel that some sellers of these heads are not doing this procedure.  

Our next step is to setup the springs up at a predetermined pressure using a spring height checking device. We set the spring pressure at what we feel to be the most suitable for street rod use. The springs we are using allow for a near perfect seat to nose ratio. Be warned that some sellers of these heads may not be checking the installed height when assembling the heads, and some that are checking this may not be setting them up to the correct pressures. We have a full scale machine shop with several very knowledgeable engine builders that know and fully understand how to properly assemble a set of heads. Combine the possibility of the possible poor assembly methods with incorrect or low grade hardware, and it is easy to see how failures can result. 

If you have any technical questions about these heads or if you need to know if they are right for your application, feel free to email us with your question, or give us a call at 423-722-5152  8am-8pm Mon-Fri or 10am-3pm on Sat.

For customer support call 423-722-5152

For overseas shipping quotes, email us using the contact seller tab or feel free to call us.


We have noticed several sellers of assembled heads using a one size fits all, hydraulic flat tappet, and hydraulic roller spring and valve setup.

We are positively sure that this is not the proper type hardware to use on your heads. When using a hydraulic roller cam, we not only use a dual spring and damper combo, but also use .200 long valves instead of the .100 long size. The .100 long valves are  used on our hydraulic flat tappet setups and with a much milder spring setup. All roller cams use a more aggressive spring setup to keep the roller lifters planted on the cam lobe. They are very prone to wanting to bounce the roller lifter away from the lobe due to the very different lobe design. These sellers using a one size fits all setup, are trying to hit a happy medium, and most head builders we know of, are completely against it, as well as many head companies such as Dart, etc. If they have this setup somewhere in the middle, then it would be too much for the hydraulic flat tappet setup, and create a serious wear issue with the cam in our opinion. Putting too much pressure on a flat tappet cam is a sure way to kill the cam very quickly. It s just another way of increasing profit for the seller without regard for the customers best interest, in our honest opinion. We setup your heads the way they should be, according to what type cam you have, and the difference is dramatic between a roller cam and flat tappet cam. Even the odd ball solid flat tappet cam has its own unique setup depending on what the lift is. The one size fits all hardware claims to also work on these cams. We know of several head sellers using this insane method of setting up heads, and it’s not correct in our very strong opinion.

 Call up any cam company, and tell them you want to use a one size fit s all setup on their hydraulic flat tappet cam or hydraulic roller cam and they will tell you this is not the correct way to set the heads up, and depending on the spring pressure, it can t serve both properly. You may experience valve float and lifter bounce on the roller setup, or extreme wear for the flat tappet cam, depending on what cam this crazy setup is closer to. We would not even consider this type hardware, and believe me, the simplicity of it is appealing.



Intake Valve Dia:                  2.02” 

Intake Port volume:              200cc

Intake Port Dim:                    2.2” x 1.2”

Int Port Location:                   Stock

Intake Gasket:                       Felpro# 1205 fits perfectly with most intakes. Should your intake drop to low, then the 1255 will 

                                              correct this problem. Our line of intakes have worked very well with the Felpro 1205 intake gaskets.

Exh Valve Dia.:                      1.600”

Exh Port volume:                   70cc

Exhaust Port Dim:                 1.356” x 1.420” w

Exh Port Location:                 Stock location & bolt pattern

Exhaust Gasket:                     Depends on what type exhaust your using. Best to try and match up the gasket to your header or manifold

Flow, Intake:                          See chart above.

Flow, Exhaust:                        See chart above.   

Head Bolts:                            Must use extended reach with true head bolt washers or head studs. See our other listings for accessories.

Head Studs:                            PC-2451-STUDS (12pt)

Manifold:                                MOST ANY

Milling:                                   Min. Down to 58.5cc or 64.5 = .060” See info in this listing for details on this.       

Pistons:                                   Most 23°aftermarket pistons.

Push Rod length:                    7.9" (also known as +100) if setup as a hyd. flat tappet. if setup as a hyd. roller 7.2 pushrods. Check this!

Push rod Guide Plate:            We strongly recommend Dart flat guide plates. See our other listings for many accessories.

Retainers:                              Steel   10°   Comp brand machined locks are used on all of our heads. 

Spark Plug:                             Straight,  .750” reach, gasket,    Autolite  3923 or NGK 4544 for one step lower heat range than the Autol.

Spring Pockets:                      1.550” OD    (.030” deeper max)

Springs:                                  Our Assembly:   1.46 outer diameter. single with a damper for hyd. flat tappet cams. Dual spring for hyd. 

                                                roller cams. 


Valve Length:                        5.015”   (+.100”) for hyd. flat tappet cams or + .200 for hyd. roller cams    

Valve Stem Dia:                     .3415”   -   11/32”

Valve Train:                           STD SBC 3/8” or 7/16” stud mount

Valve Guides:                        1/2” OD   Int = Mag-bronze      Exh = Phos-bronze (.002” press)

Valve Guide length:               1.950”        

Valve Guide clearance:         .0014” - .002”   (with our .3415 dia. valve stem)

Valve Guide Spacing:            1.890”   moved .030” from stock

Valve Seats:                           Hardened Ductile Iron,   .006” press    

Valve Seat dim.                       Standard

Valve Seat angles:                 Int = 32° - 45° - 60° - 70°       Exh = 37° - 45° - radius                     

Stud Girdle:                            Use any standard girdle

Torque:                                   Head Bolts = 65 ft/lb

                                                Rocker Studs = 55 ft/lb

                                                Manifold = 35 ft/lb

Block Use:                              Any SBC Iron or Aluminum  

Weight:                                   59-61 lbs fully assembled pair.

 Important installation notice,

As with any new heads, you must do a mock setup with the heads before bolting them on. This is done by setting the heads on the engine and using two bolts to hold the heads in place. This will allow you to check your pushrod clearance, and that your rocker studs are all in line. If your pushrods are touching any surface of the heads, you will have to dremel these spots for clearance. Rarely will this have to be done, but in some cases it may need to be. We have seen this situation with many aftermarket heads, including Dart. There are areas of the casting that are very close to interfering with pushrods, and will only take seconds to correct, but you certainly don t want to have completely bolted the heads on and find this out. We received a large order of Dart heads that had an interference issue with the pushrods, and as mentioned it only takes seconds to correct this with a dremel tool, but not if you have secured all 34 head bolts. You can not correct such issues with the heads on the engine due to the risk of contamination of the rest of the engine. See our other listings for items you may need to complete your engine build. 

If you have been a regular shopper with us, you will have noticed we do offer some knock-off products that are made off-shore. We do also sell many products made in the USA. We have always been very particular as to the quality and workmanship of such products, with consideration of the cost. We scrutinize our products very carefully and refuse to sell products that simply don t meet our standards, all things considered. We have now eliminated another of the low cost knock-off products from our line. The low cost rocker arm studs being imported have shown numerous problems unlike those in the past. We have looked at several others on the market, and still find many issues with them that are not acceptable. The most serious issues were the fact that many of the studs had run-out in the shaft up to 150 thous. This caused major problems with rocker alignment, and depending where the position was when the stud tightened, would determine the direction of the misalignment. If the stud position was facing the valve, then the roller tip would not run off to the side of the rocker but it would cause the roller tip to not be centered on the valve. This would then create a loss of lift, but there was another issue that concerned us most of all. The warped stud shaft of some of these studs would allow the rocker tip to set cocked on the valve tip more or less, depending on what position it tightened up at. This would then side load the valve tip with undo pressure creating a serious wear problem on the valve tip and valve guides in the heads. This also side loaded the rocker trunion, and front roller creating an excessive wear issue in the roller rockers. We also found the difference in the tread pitch and depth to be dramatic compared to the ARP studs, and as you know the rocker studs in an engine are under a tremendous upwards pull and improper thread design will cause the studs to possibly pull out of the head. The ARP studs screw into the heads with a very precision fit and feel. After doing a thorough comparison between the ARP studs and several off shore models, I am convinced that we will never offer them again regardless of the price difference. They were never as bad in the past as to what were seeing now. This run-out was most likely caused by improper heat treating methods.
We are glad to offer many of the low cost items that are off-shore, but will always give careful consideration to quality, functionality, and overall value. The after-market rocker studs will never ever be sold by us again. 
You will notice that we offer many USA made products, but do not offer that same item in an off-shore line. It certainly is not because we don t have access to the low cost off-shore product, but because of quality issues that we have discovered. Getting a good value is very important and working within your budget is the only way many are able to complete their project. We have rejected many products that are outright junk and would cause serious issues in your engine only to see other sellers offering those same exact products. It s all about learning where to draw the line. As far as I know there is only one other rocker arm stud besides ARP on the market that is of decent quality, and that s from the GM Performance division, and it s fair to say they are most likely supplied to GM by ARP under private label. 

It is recommended that if you are running full roller rockers, then you most likely would require tall valve covers, and this can cause the oil that is pumped up into the top of the heads to not be deflected back down onto the valve springs, valve tips and roller rockers. The lack of oil on these parts can lead to not only a lack of lubrication but also a lack of cooling on these parts. Heat transfers up the valve stem from the combustion chamber. This heat is very high in temp, and may cause serious damage to the valve guides, springs and roller rockers. The cure for this would be to install a low cost set of stud girdles. Stud girdles increase stability to the rockers studs eliminating flex that is usually always present to some degree when running cams several sizes over stock, not to mention increased spring pressures over stock. Stud flex robs your engine of power and smooth operation in the upper rpm ranges. But as mentioned above, another very important aspect of using stud girdles is that they deflect oil directly back onto the valve springs, valve tips and roller rockers. On a stock engine this is not an issue due to the fact that stock valve covers are very close to the top of the rocker arms. If you have ever had the valve covers off on an engine while it is running you would notice that the oil sprays up out of the back side of the rockers and goes in all directions. The most important reason that oil is brought up into the top of the engine is for lubrication and just as important is to cool the valve train components. The oil temp does have a great cooling effect, as it s temp is only around 215 deg. and the heat that is transferring up into the valves and springs if far greater than this. Without oil being flushed onto these parts lack of lubrication would be just one of it s problems. Valve guides and stems that are heated up to high temps, and also lacking the proper amount of lubrication may experience excessive wear. We suspect that these parts may be suffering due to the oil not being redirected back onto them, and stud girdles would positively protect these parts to a great degree in our opinion. We now use them on every engine we build regardless of how mild the cam and spring pressure is. Those running cams that are above 460 lift should run them as this is about the level that stud flex may come in, especially when running the smaller 3/8 s rocker studs. Excessive valve guide wear along with other valve train components can be very expensive to repair. 
Skip White

A final note,

Our eBay user id is: skipwhite, and our eBay store name is whiteperformance1. You may have noticed other sellers using a similar name offering similar products. These other sellers have capitalized on our name as we see it, and many customers searching for us will inadvertently find them, thinking we are one in the same company. There is only one "Skip White" We are the original premier eBay seller under this name since approximately 2002. We have no other eBay names, nor are we associated with any other company regardless of the similarity in the name or location. Our official company name is Skip White Performance.

Skip White 

If you have any questions about these heads or if you need to know if they are right for your application, feel free to email us, or give us a call at 423-722-5152  8am-8pm Mon-Fri or 10-3 on Sat.



If you checkout and start over, the auto calculator will not recognize the multiple purchases, and there will be no shipping discount. Should you decide to start purchasing again after checking out, you will need to contact us so we can calculate your shipping for you.



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FedEx Home Delivery delivers Tuesday - Saturday. If a package leaves here on a Thursday, and you are in a 2 day delivery zone, your package will deliver to you on Saturday. If you are in a 3 day zone, and your package leaves on a Thursday, you will not receive it until Tuesday. Expedited shipping is available upon request for an additional fee. Please contact us for rates.

Hawaii and Alaska have a 6+ day estimated delivery time.

The shipping quoted in this ad is only for the 48 continental United States. If shipping to anywhere else, please give us a call or email us for quotes. The half price shipping on all additional items also only applies to items that are being shipped in the 48 continental United States. If you have any questions, you may give us a call at 423-722-5152




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