[Holeshot71]

Originally Posted by gtofreek

The brand new manifolds out of the box were warped BAD! When I set them on the granite slab, there was probably a .040" bow in them. This has been the case with most of these manifolds I have installed new. So we took them and surfaced the gasket surface until they were flat. The steel gasket should work fine with them. Out of the box I could see you having to use the Fel-pro blue header gaskets or some Remflex. After surfacing them, they were flat so there should have been no need for special thick gaskets.

What I meant by surface mismatch was the exhaust ports were not lined up with each other and the gasket didn't crush. I believe it was a corner of one of the end ports.

I'm not saying this is the problem, it's just something I came across on the 455 I just built and thought it might be something to check.

When I'm listening for noises I prefer to use a 3' section of 3/8" rubber hose, one end to my ear. It really helps to isolate surrounding noises and helps to pinpoint where a noise is the loudest.