To expand on what Mark stated, the gaskets used, although the quality of which has a marked effect on seal, is secondary to the exhaust manifolding/header one uses. One needs to determine whether the thickness of the flange is adequate. I believe the weak link in a gasket dependability/durability issue is the stability of the manifold/header under the abuse of the higher heat environment of a turbo system.

 

damn, those norlocs look cool. Anybody used them with luck? I saftey wired mine, but man is it a bitch when I have pull 'em.