Should I go w/ headers or stick w/ factory manifolds? Do I need to tap the head for the bolt patern to fit?

Question

I have a 72 Pontiac GTO 455 H.O. 4 speed, the factory manifolds have been resurfaced and I added a copper gasket, but they continue to develope leaks, I know headers tend to leak and they are hard to find for round port heads, but I don't know if the head needs to be drilled for a header bolt to bolt into the end of the head to create a good seal. By the way I have the stock heads and a large cam with a .030 over engine bore.

Answer 1

I recommend to anyone that drives there HO or RA cars more than just show... GO with the Headers and save the Orginal Manifolds and reinstall them when you sell the car.... If the loss of point matter's to you stay with Factory headers...

You will have to replace gaskets every 2 years or 3...Still

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Good Question........

Answer 2

I would go with headers on a car like that. Those 455's need to breath. You will be able to get headers for that car that fit the stock pattern. When you go to install them no matter what type of gasket you use do the following; 1. Only barely snuggly tighten the header bolts down on both sides. 2. Turn the car on and let it run for around 3 to 4 minutes. 3. Then turn the car off and tighten the header bolts to the reccommended torque settings. This gets the gasket hot and it expands then you tighten the headers down onto that and it causes great adhesion. You won't have any leaks.

Answer 3

Factory headers are also a good, low maintenance choice. These are an upgrade from the stock manifolds, but I believe they will bolt to an existing stock type exhaust system (you have to change to a 3 bolt flange on the header pipe).

DON'T tap new holes in the heads!