If your plug wires or the boots are less than half an inch from the headers, it's a 100% chance that they will be damaged in a very short time. This damage will lead to voltage leakage and engine misfire. Rule of thumb is a minimum of half an inch clearance and even at that, it's not the most ideal amount. If your wires are run above the headers, then the distance has to be greater than half an inch.

We have seen it over and over, burned up plug wires arcing intermittently and causing engine misfire. If you have ever seen the typical Chevy 350 exhaust manifolds that were designed under the plug wires, you may remember these had a sheet metal heat shield right below each pair of plug wires. After many years, the screws that held these shields in place would rust and break off, and the shields would often remain in place but many people would remove them. The distance appeared to be ample from the ex. manifold to the plug wire, but the wires would be destroyed in a couple months in every situation that this was done. The word out was to never remove these shields even if the screws were rusted away.

The solution to protect your plug wires is to use header wrap, heat shields or plug wire fire boots as we’re offering in this sale. Under the right conditions, some wires will not last more than 200 miles from the damaging effects of excessive heat. Your wires may actually look OK, but the protective properties have been cooked out of them.

Open your hood at night while your engine is running and you may see evidence of this. I have seen it on many occasions. Take notice of the elaborate heat shields between the plug wires and exhaust manifold on many modern cars and you will see that the factory takes this seriously.