Scat Crankshaft

The picture below is a generic file photo of a Scat crankshaft. You will receive the correct model packaged in the original Scat box.

Some of the benefits of the Scat crankshaft:

The material used in this crankshaft is manufactured from an exclusive Space Age material that was designed for high strength and fatigue resistance. The Scat cranks are the best value you will ever find. The Scat crankshafts are the best way to build a strong bottom end for, street rods, dirt and circle track racing, and drag strip racing. This crank is suitable for use up to approx. 800+ hp. 

We recommend that you check the thrust clearance on the crank before assembling the engine. This is recommended on any crankshaft, regardless of brand or cost. Also be sure to check your main and rod journal size.

Scat connecting rods.

Genuine Scat Bushed Rods with ARP 12 point cap screws are now used in all of our rotating assemblies and 383 Stroker engines.

As seen the in close-up picture below, Scat rods have a very solid build quality.

The quality of the Scat rods is unsurpassed by any of the low cost no-name rods on the market and they exceed the quality of some of the branded names as well.

Our Scat rods are bronze bushed. These are far superior to press fit. They are much more durable and free up a slight amount of horse power, and reduce piston and oil temp. This is something to consider when buying kits that use press fit rods. We just don't recommend press fit to anyone. Machine shops will charge up to $60.00 to press them on. Bushed rods with full floating wrist pins, which we offer, are very simple to attach to the pistons. 

The Scat rods do have genuine ARP 8740 Series 12 point cap screws. These rods offer excellent block clearance in the lower end of the cylinders.

We have noticed some sellers using generic rods and crankshafts in their rotating assemblies. These non-branded (no-name) rods and cranks are often poor quality in many ways. You will notice many sellers fail to mention the actual brand of these products. Upon further investigation, you will find such parts not to be a branded name product. They may label these parts with a name, but one that is totally unrecognizable in the industry. Our experience in years past with such rods and cranks has been disappointing, to say the least. Failures of such critical parts in your engine may result in catastrophic damage. Machine shops are sometimes able to correct some of the problems with these low quality rods and cranks, but at great expense to the customer. As for the questionable alloy these items may be produced from and the potentially incorrect heat treating methods used, little can be done to verify this and nothing can be done to correct it. As you may have noticed, this is why we specify the name, brand, and series of every part used in our assemblies.

Many of the inferior "no-name" rods on the market will also have "no-name" rod bolts in them. We have seen these bolts before, and they are very low quality. They don't have ARP's rolled thread design, and they don't torque down with the same characteristics as a genuine ARP bolt. It's not just a matter of having a different brand bolt in the rods; these bolts are low quality in many ways. They have been known to fail in engines to a much greater degree than a high quality rod bolt, and this failure usually causes catastrophic damage in the engine. Beware of rods that don't mention the rod bolt brand. As far as we're concerned, ARP bolts are the only brand we would ever use or accept in a set of rods.

Genuine ARP 8740 cap screws.

The Scat rods do have genuine ARP 8740 Series 12 point cap screws. Some cams may require slight clearancing of the rods. Be sure to do a roll over test after installing each rod. 

We have noticed some engine builders using low cost generic rods and crankshafts in their engines. These non-branded, (no-name) products are often poor quality in many ways. You will notice many of the low end engine builders fail to mention the actual brand of the rods or cranks used in their engines. Upon further investigation you will find such parts not to be a branded name product. They may label these parts with a name, but one that is totally unrecognizable in the industry. Our experience in years past with such rods and cranks has been disappointing to say the least. Besides the obvious issues such as incorrect sizing and machining that is difficult to correct, the questionable alloy these items may be produced from and the potentially incorrect heat treating methods used, could prove to be disastrous. Little can be done to verify this and nothing can be done to correct it. Failures of such critical parts will usually result in catastrophic damage to the engine. As you may have noticed, this is why we specify the brand name and series of every part used in our engines.

Many of the inferior "no-name" rods on the market will also have "no-name" rod bolts in them. We have seen these bolts before, and they are very low quality. They don't have ARP's rolled thread design, and they don't torque down with the same characteristics as a genuine ARP bolt. It's not just a matter of having a different brand bolt in the rods; these bolts are low quality in many ways. They have been known to fail in engines to a much greater degree than a high quality rod bolt, and this failure usually causes catastrophic damage in the engine. Beware of rods that don't mention the rod bolt brand. As far as we're concerned, ARP bolts are the only brand we would ever use or accept in a set of rods. 

Before the engine is assembled, we strongly suggest checking the rods on a Sunnen machine for sizing on both ends. We recommend this with any rod regardless of cost or brand. It is not uncommon to find some of the rods requiring a slight bump through the hone for perfection in sizing and roundness. We also offer this kit with a proofed set of rods. This is an excellent choice for those wanting to build the engine on their own. 

MAHLE FILE FIT RINGS INCLUDED.

 KING MAIN AND ROD BEARINGS INCLUDED.

HEAVY DUTY FLEXPLATE INCLUDED. 

HEAVY DUTY FLEXPLATE. This flexplate will resist cracking. One good telltale in identifying a low quality flexplate is the lack of welding on each side where the plate mates to the ring gear. They usually have a pale grey color to them, as they are not coated, and will rust quickly. Ours are welded on both sides, and are much thicker than an OE plate, and are either zinc dichromate or black powder coated. We would never use the thinner OE style plate on an assembly like this. 

We do offer this assembly with a manual flywheel. See our other listings. In most cases we do have both sizes, 153 and 168 tooth, available.

WARNING: The crank has a dowel pin installed in it. You must align the flexplate or flywheel to the dowel pin. The assembly was balanced with this pin installed.

 Our CWT 5500 Balancer.

We do our own balancing with our new state of the art CWT 5500 Series balancers. The CWT 5500 is the ultimate for precision balancing. We now have three of these in our machine shop. We consider this machine to be highly advanced compared to the Hines balancer we once used. We balance every rotating assembly we sell within 2 grams or less at no extra charge. A balance sheet is included with your assembly. 

Three CWT balance machines under one roof is a rare sight. 

Our crew wrapping up for the day. Pardon the mess.

Rust warning.

If you are going to store your rotating assembly or short block kit for any length of time, it is very important that you protect these parts by spraying a light coat of rust preventive substance on all bare metal parts. This is especially important for those storing these parts in a high moisture or humid environment. Very light surface rust is easily removable and will cause no harm, but heavy rust can damage these parts and be very costly to fix.

Our thoughts on what the competition has to offer.

Many short block kits we see on the market are not using the most suitable parts. We hope you can value the fact that we have put together an above average short block kit. The failure rate with the parts we use is near non-existent. It was through trial and error in years past that taught us where to draw the line with low cost parts. We are out-priced by many others selling short block kits that include parts with high failure rates. Many of these parts also pose a great problem due to the fact they require additional machining and can end up costing you a great deal more money and time. If you're going to have a machine shop build your engine, we strongly advise you get an opinion from them on the parts you're going to be bringing to them. Rest assured they will find no problem with the quality of our parts. We have also seen sellers offering parts that are not compatible with what most people are building. We have seen several sellers offering no-name brand rods with an assembly. These type of rods also have no-name bolts in them. It is our strong advice to avoid this grade of rods. The low grade dampers and flexplates are also another problem. Another area of concern would be balancing. Not sure how much attention these sellers are giving in this area. We spend up to two hours balancing an assembly, and using the very best up to date balancing equipment on the market. If the assembly is not balanced properly, it will hammer the bearings out of the engine, not to mention there is nothing worse than an engine that lacks a smooth feel and sound when under load.

We offer this assembly with selected upgrades. Listed below are some of the most requested ones. Many not only improve performance, but further enhance the reliability and longevity of your engine, along with resale value.

Note: The upgrade prices below are subject to change. Refer to the actual upgrade listing for the exact price of these upgrades. The changes are usually very small if any.

SFI Certified Flexplate: This is a very low cost upgrade and may be required when racing your car at certain tracks. The flexplate that comes with this assembly is a heavy duty plate, but the SFI certified plate is one step up in quality and safety. This SFI plate is made in North America. We noticed these have much less run-out and warpage than we see with many other plates on the market. Plates with too much run-out and warpage can cause a host of problems for your transmission and starter, and affect balancing. The low cost to upgrade to this is well worth it in our opinion.

Cost of this upgrade is $18.50 We have this upgrade featured in our other listings. You can see this and other upgrade options in our ebay store under the "UPGRADES" category, or simply do a search with the key word, "Upgrade" in the search bar when shopping in our ebay store. Before you finalize your purchase of this assembly you may add any of these upgrades to your shopping cart.  

SFI Rated Billet Steel flywheel upgrade/option for manual transmission. Upgrade to a SFI billet steel flywheel 168-tooth or 153-tooth for manual transmissions. We highly recommend the SFI billet steel flywheel for those running hard. These are fully cnc'd and far superior in many ways compared to the regular cast iron flywheel.

Cost for the SFI billet flywheel option can vary depending on availability. We carry two lines of the SFI plates, PRW and Ram. The Ram plates are a much higher grade product. We have this upgrade/option featured in our other listings. There will be a Chevy 153 tooth and a Chevy 168 tooth size available. Be sure you know the size you need. You can see this and other upgrade options in our ebay store under the "UPGRADES" category, or simply do a search with the key word, "Upgrade" in the search bar when shopping in our ebay store. Before you finalize your purchase of this assembly you may add any of these upgrades to your shopping cart.

Crank polishing: Extends bearing life, reduces oil temp, frees up a slight amount of average horsepower. This is a very low cost upgrade, and in the world of mass production, most cranks do not come with a true polished finish. This is why most machine shops have a machine to do this. The difference is dramatic between a crank right out of the box and one that we have polished. Bearing companies claim that cranks that have better finishes on the journals will survive the break-in better, and have much longer bearing life. We do a two-step process and bring the RA numbers down in the single digit range. We have the most advanced crank polishing machine on the market. 

Cost for the crank polishing upgrade is $38.50 We have this upgrade featured in our other listings. You can see this and other upgrade options in our ebay store under the "UPGRADES" category, or simply do a search with the key word, "Upgrade" in the search bar when shopping in our ebay store. Before you finalize your purchase of this assembly you may add any of these upgrades to your shopping cart.  

Clevite Bearings: We find the Clevite bearings to be a somewhat better product overall. Clevite is what we now use in all of our engines. This is not to say that King bearings are faulty in any way, but under certain conditions, we have seen fewer problems develop with Clevite bearings during break-in. We have sold King bearings for many years and do not hear of problems from our customers, but our experience on the dyno has shown the Clevite bearings have a better surface appearance upon tear-down after many dyno passes. This is due to the fact that Clevite A series bearings use a slightly harder aluminum alloy.

Upgrade to Clevite "A" Series bearings is $17.50 (These are what we use on all of our engines that have a cast nodular crank.)

Upgrade to Clevite "H/HN" Series bearings is $106.00 (Use only on 4340 forged crank upgrade.)

We have these Clevite bearing upgrades featured in our other listings. You can see these and other upgrade options in our ebay store under the "UPGRADES" category, or simply do a search with the key word, "Upgrade" in the search bar when shopping in our ebay store. Before you finalize your purchase of this assembly you may add any of these upgrades to your shopping cart.  

Rod to cam clearance and sizing: We know exactly where and how much to cut the rods on our vertical milling machine for correct cam clearance, and sizing the big end and wrist pin bushing on the Sunnen machine saves a trip to the machine shop. All rods, regardless of brand, should be checked for sizing on a Sunnen machine, and corrected if needed. You will seldom see a complete set of rods that have  perfect sizing on both ends right out of the box.

Cost of this rod to cam clearancing and sizing upgrade is $68.50 We have this upgrade featured in our other listings. You can see this and other upgrade options in our ebay store under the "UPGRADES" category, or simply do a search with the key word, "Upgrade" in the search bar when shopping in our ebay store. Before you finalize your purchase of this assembly you may add any of these upgrades to your shopping cart. 

We do the rod to cam clearancing on a vertical milling machine as pictured below as part of this upgrade. By doing this procedure on a milling machine the rods are cut precisely at the correct angle to clear the cam. This also keeps the amount removed identical on each rod. It would be very difficult to do this by hand on a grinder as is commonly done. After we clearance the rods on the milling machine we go over them on a wire brush machine to clean up the edges, and remove any stress risers. This is a very critical procedure. Those who lack the experience and choose to do this on their own risk destroying the rod and or the bolt, or at least removing too much material and weakening the rod and or bolt.

Race balancing: This is for those who want the engine to operate virtually vibration free at high rpm. Extends engine life and frees up a few more horse power. This is a somewhat labor intensive procedure and is not required, but the feel of an absolutely vibration free engine at high rpm is desirable by many. The standard balance job that is included with this assembly at no extra charge is certainly sufficient. With a race balance job, all pistons and rods are match weighed to within 2/10's of a gram or less, and the final balance is brought down to around 1 gram plus or minus. An ultra smooth engine at high rpm has a noticeable feel and sound to it. If you do not opt for this upgrade, the assembly will still be fully balanced. We spend a good hour and a half doing the regular balance work, and it will certainly meet your needs.

Cost of this race balancing upgrade is $125.00 We have this upgrade featured in our other listings. You can see this and other upgrade options in our ebay store under the "UPGRADES" category, or simply do a search with the key word, "Upgrade" in the search bar when shopping in our ebay store. Before you finalize your purchase of this assembly you may add any of these upgrades to your shopping cart.  

Scat Competition Rods: Recommended for those running hard. The regular Scat rods that come with this assembly are sufficient for most street rod uses, but the Scat Competition series rods offer more security against rod breakage under hard use, and they have the huge ARP-8740 7/16's cap screws. The Competition rods have a 600+ Hp rating, and the slight cost to upgrade is well worth it in our opinion. These rods require slightly less cam to rod clearancing then the regular Scat rods. We use the very same Scat Competition rods in our 600+ hp 427 and 434 engines.

Cost of this Scat Competition rod upgrade is $65.00 We have this upgrade featured in our other listings. You can see this and other upgrade options in our ebay store under the "UPGRADES" category, or simply do a search with the key word, "Upgrade" in the search bar when shopping in our ebay store. Before you finalize your purchase of this assembly you may add any of these upgrades to your shopping cart.  

ARP-2000 rod bolts: This is one upgrade that we find to be very valuable. The rod bolts are most likely to fail under hard use, moreso than the rod itself. When a rod bolt fails during high RPM, total engine destruction is usually the result. The ARP-2000 rod bolts are a very good upgrade, in our opinion. We actually have few, if any, problems with the regular ARP-8740 bolts, but those who run hard always upgrade to the ARP-2000 rod bolts. The ARP-2000 rod bolts also torque at a higher number, and this increased clamping force is also a factor in keeping the big end of the rod stable and true to size. The ARP-2000 bolts are installed in the rods and this upgrade is only available with the Competition rod upgrade. 

Cost of this ARP 2000 rod bolt upgrade is $89.50 We have this upgrade featured in our other listings. You can see this and other upgrade options in our ebay store under the "UPGRADES" category, or simply do a search with the key word, "Upgrade" in the search bar when shopping in our ebay store. Before you finalize your purchase of this assembly you may add any of these upgrades to your shopping cart.  

Scat 4340 Forged Crank: The forged Scat crank has a rating of 800+ HP. This is the ultimate upgrade for those wanting to run hard. Nos, blowers, turbos, are not an issue with this crank. Even without such power adders, this Crank offers great protection under the most severe conditions. This upgrade also comes with the HP high Performance King bearings. Should you decide to run power adders in the future, this would be essential. The fatigue life of the 4340 crank over the cast nodular is also greatly extended. We do offer this upgrade as part of many of our assemblies in some of our other listings. They have the key words, "fully forged," in the title.

Cost of this forged crank upgrade is $460.00 We have this upgrade featured in our other listings. You can see this and other upgrade options in our ebay store under the "UPGRADES" category, or simply do a search with the key word, "Upgrade" in the search bar when shopping in our ebay store. Before you finalize your purchase of this assembly you may add any of these upgrades to your shopping cart.  

The upgrades above are all available in our other listings. Some of these are often requested by those building an engine without a machine shop. We find most of these upgrades very valuable for those wanting to take longevity and durability to the next level. They are all bottom end related, and that's an area worth investing a few more dollars into, in our opinion, especially if you're planning on running long and/or hard. These upgrades are also valuable for your build history on your engine, and would certainly increase the resale value of your engine, should you ever sell it. 

Transmission Recommendations by Skip White

Your selection of what type transmission you're going to use with your new engine is very important. I'm going to give you the real lowdown on what transmissions I recommend, as well as the ones I would stay away from. For those building a mild, (detuned) street rod, (small cam choice, dual plane intake) these recommendations are not as critical. We offer an excellent line of automatic performance rated transmissions built by TCI. The quality and cost are excellent.

700R4: Worst possible transmission choice when used with moderate to high horse power engines. 

Pros.

• Driving at 50 and above in overdrive certainly has its advantages such as increased fuel mileage, reduced wear and tear on the engine, less engine noise, reduced emissions/pollution.  
• Fuel injection/EFI does make this transmission operate much better providing the cam choice, intake manifold and final gearing are setup correctly.
• To setup an engine to operate properly with this transmission requires a detuning of the engine and top end horse power is greatly reduced. 

Cons

• Very wide first to second gear spread. First gear is a 3.06 ratio Second is a 1.62 ratio. This nearly equates to skipping from first to third gear with a manual trans. This kills acceleration when these trans go into second gear on a carbureted engine with a healthy cam and large runner intake manifold. Compare this to a TH350. First gear at 2.52 ratio and second gear is 1.52, do the math.
• The 3.06 first gear is so low that any final gear of above 3.55 or numerically higher will have you right at the  max rpm at around 35 mph, only to then have your car fall on its face when it hits second gear, feeling like it skipped a gear. Wheel spin is uncontrollable upon hard launches, unless you have a very tall final gear, and then you can for sure count on going nowhere quickly when second gear comes in. Overdrive would be totally useless at highway speed regardless of detuning with a tall final gear, unless you were cruising at around 100 mph.
• Huge cost to build up to a decent street rod level. Don't even consider a stock rebuild to handle 500 hp or more. Under hard use, the 700R4 will fail quickly. 
• Limited as to what level these can be built up to. High performance transmission builders and parts suppliers don't even recognize this as a serious transmission.
• More complex to build than a TH350 and far more expensive, especially when built up to handle high hp numbers.
• Having to run a cumbersome throttle value cable to the carb. linkage. This feature actually serves a good purpose, but if not set properly, it can destroy your transmission quickly. Very critical adjustment, and often overlooked. Our TCI built 700R4 transmissions do not require the throttle value cable should you decide to run this type trans. 
• The overdrive is actually useless with engines running decent size cams relative to the cubic inch, especially with large runner dual plane intakes, and single plane intakes are out of the question with this trans. The exception to this rule would be those running a Holley Sniper EFI system, and a low profile single plane intake. 
• Stall converters are double the cost of the one run in a TH350.
• This is  not a very reliable transmission in a street rod.
• Lowers the value of your vehicle to some degree, especially on high hp builds. These transmissions do not belong in most carbureted street rods. You must detune an engine considerably to operate the overdrive and be able to tolerate the first to second gear drop.
• Could be classified as the worst mismatch of parts known on a true street rod.
• As a side note, I would like to mention that most of us have owned a regular stock street car with a 700R4 trans, or its electronic likeness, a 4L60E, and didn't find much of an issue with the way they operated, especially if the vehicle was fuel injected. This is because stock car engines are designed to operate totally different in the very low rpm range. They have huge amounts of off idle torque compared to the average carbureted street rod that makes 400 hp or more. This off idle instant torque allows the vehicle to keep its speed up decently when the 700R4 drops into second gear, and the same low rpm also allows the overdrive gear to operate normally at very low rpm. There are other factors that also allow these trans. to operate at low rpm, especially on fuel injected computer driven engines.

TH350: Best transmission choice, hands down.

Pros

• Excellent gear spread between all three gears.
• Very low cost to build up to various levels of power handling.
• Can be built up to extreme power handling capabilities.
• Most all transmission shops are capable of building these to at least level 1 or 2.
• No TV cable to deal with.
• Stall converters are low in cost, and the selection is broad. 
• Very reliable and simple to repair if needed.

Cons

• None, simply none! Select a final gear that will allow you the best overall performance and one that allows a decent off the line acceleration, and one that will be in a tolerable rpm range at highway speed. You must have the correct stall converter for optimal performance. This can make a huge difference in the way your vehicle accelerates.
• These are becoming scarce, but there are still plenty of them around, and high performance parts are easily obtained.
• You may have to go through this long story to your less than knowledgeable friends as to why you didn't choose a 700R4, and when you explain it to them, they may still think you don't know what you're talking about.

TH400, Excellent choice for high powered engines in heavy cars or trucks.

 Pros

• Excellent gear spread. Very similar to a TH350.
• Very strong internal parts.
• Reliable.
• Simple and inexpensive to rebuild or repair.
• Best suited when running high powered big block engines in medium to heavy vehicles.

Cons

• Somewhat expensive to build up to higher power handling levels, as compared to a TH350. The TH350 has far more high performance parts available at reasonable costs. The 400 trans is not best suited for racing.
• Internal rotating parts (cast iron drum) are very heavy and create a drag compared to most any other trans. The TH400 is well known to be a heavier duty trans. than a TH350 but this heavy duty factor was designed more for heavy vehicles coupled with high powered engines that may encounter pulling heavy loads or vehicles with tall gearing. Only the largest of the GM cars weighing around 5000 lbs had these trans. in them, along with heavy duty pickups, usually 3/4 ton or larger trucks. Even the half ton Chevy trucks didn't come with these in them.
• They will certainly hold up better than a stock built TH350, but they are not a desirable trans. light weight street rod with a small block engine in it. You can build a TH350 to level two or three that would be superior to any stock TH400 in every way for about the same cost. We offer the TH400 trans built to level 3 and this trans. is best suited in high powered big block engines, in cars that are medium to heavy weight.
• You will seldom see this trans in a true light weight Pro-Street car.

Powerglide.

 Pros

• Excellent transmission to build up to just about any power handling level.
• Most trans. shops are able to build this trans with ease.
• Very reliable, and simple to work on. Not much to go wrong.
• Decent first to second gear spread.
• Rotational drag is very low with this trans., more so than any automatic on the market. Very efficient trans.
• Stall converters are not expensive and many choices available.
• Often used in 1/8 mile drag racing. 

Cons

• Two gears, that's the problem. This trans. can only be run in cars that have a very high hp to weight ratio. It would be fair to say a vehicle weighing approx. 3400 lbs would require an engine output of 1000 hp or more to make it a rational choice, and even then, you would still need a decent final gear to get things moving off the line. The first gear in these is somewhat tall. Those running a T-Bucket roadster weighing around 1800 lbs. with a 500 hp or higher engine could make great use of a Powerglide trans.
• Having only two gears limits having the best of both worlds when it comes to off the line acceleration and cruising at highway speed. The final gear choice limits the general use of your car greatly. 
• This trans. will not allow a car to be setup for the best of both worlds, such as street cruising, racing, or highway driving, unless the car is extremely light, and the engine has very high HP numbers.

GM METRIC 200

 Pros

• Has a better gear spread than the 700R4 but not as optimal as the TH350.
• Not much good to say about this trans. It certainly has a place in some special late model applications, but old school Chevy engines is not one of them.

Cons

• This transmission can cost up to three times more to build up to a decent power handling level compared to a built up TH350.
• Cannot hold up to high torque engine builds unless an enormous amount of money, (Art Carr) is spent on this trans.
• Most all the cons you see for the 700R4 exist within this trans.
• This trans is not a reliable trans. compared to any of the early GM trans unless a great amount of money is spent building it.

4L60E Electronically controlled trans.

 Pros

• No TV cable to deal with or shifting linkage. It has pump pressure control and shifting via electronics.
• Not much good to say about this expensive trans. It is virtually a 700R4 with a modern twist. The same "pros" mentioned with the 700R4 would apply to this trans. also. The 4L80E trans. is a better choice due to the fact it has a proper gear spread, and is a much heavier duty trans vs the 4L60E.  

Cons

• Most of the same issues as the 700R4. Terrible choice to run in an old school carbureted engine.
• Very expensive to build up to a high power handling level. Can cost up to $4,000 to build this trans up to a decent level. Computer controlled engines may require this unless you bypass the car's computer system.
• Complex. Very complex!
• Pointless to run such a terrible transmission.
• If you insist on such a trans, the 4L80E is a better choice, as it has a normal gear spread, and is a much stronger trans. Still pointless to use with an old school carbureted engine in my opinion.

Four and five speed Manual Trans.

 Pros

• Excellent acceleration at any speed due to many selective gear ratios. Finding a gear at any cruising speed to hit it hard is easily accomplished with a manual compared to an automatic.
• More efficient delivery of horse power to the rear wheels with a manual trans. versus an automatic. In other words, less loss of power due to slippage as encountered with an automatic trans.
• For some people, the fun factor of shifting gears is one of the high points of owning a street rod. 
• Very reliable, long lasting. Low maintenance. Simple to change out a clutch if needed.

Cons

• Can be very expensive to purchase a high quality modern manual trans. and high performance clutch and flywheel, especially the Tremec Series.
• Can be somewhat complex to change over from an auto to a manual trans.
• If you think your car is going to run faster with a manual versus an auto, you will be greatly disappointed. The automatic transmission can not only shift much faster, but off line acceleration can be controlled to a much greater degree. This is why most drag cars have automatic transmissions. All things equal, a car equipped with an auto trans will outrun one equipped with a regular street rod manual with great ease.
• Missing gears when racing can cause damage to your engine, and loss of control of your vehicle should you drop into the previous gear during an aggressive run. Been there a couple times, dropped a valve in brand new Lotus Esprit shifting out of second into first rather than third, and locked up the back wheels on a Dodge Viper shifting into second rather than fourth at high speed. Nearly lost control of the car at around 80 mph.
• If you're deciding to run a 5 or 6 speed manual trans because of the overdrive gear, be aware that most engines built with large lopey cams, and single plane intakes running a carb will usually not allow effective use of the overdrive gear.
• Tremec T56 transmissions are very popular and highly advanced. They are expensive. They tend to be very notchy to shift when new. Takes many miles before they become easy to shift. They can be difficult to install in some early model classic cars, as they are huge compared to early model transmissions. They can cost a great deal of money to rebuild if needed. Still about the best manual trans out there, and can handle very high hp levels. The 6th gear in these transmissions is a double overdrive and will never be useful when running any old school street rod engine unless you are running a very deep final gear. 
• If your engine is built in the upper horsepower range, then you must run a level two or three clutch kit. These clutches are notchy and lack a smooth engagement like a stock clutch. This is very noticeable, and you will adjust to this after a while. A stock clutch can not be used on any engine in the 500+ hp range. 
• Sadly, your wife may not be able to drive your car with a manual trans. This could be a plus in some cases.

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 2003. 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. Please see the article below for a more detailed explanation.

The real story...Skip White Performance vs. White Performance & Machine

Now you know the real story, and we hope this helps with the confusion.

 

OUR COMPANY FOUNDERS PRO STREET HYBRID 240Z CAR. IT HAS ONE OUR BRAND NEW SBC 427 ENGINES IN IT AND ONE OF OUR TCI SUPER STREET FIGHTER TURBO 350 TRANSMISSIONS. THE CAR IS IN FULL PRO STREET TRIM. SKIP HAS THE CAR UP FOR SALE NOW. HAVE NOT HAD IT TO THE TRACK YET, BUT WE ESTIMATE IT WILL RUN A 9.5 GIVE OR TAKE. RUNS ON PUMP GAS. HE HAS OWNED IN FOR THE PAST 15 YEARS.