Yeah, I checked with a straight edge and I had exhaust leaks mainly. My manifold was 47 years old so who knows, but I couldn't see any signs of warping and the head looked straight as well. When I converted the old engine to headers and the new intake I used the gasket clifford offered and never had any leaks since. One point to be sure of...the felpro metal gasket will Not work with clifford headers to do the interesting flange design. lol I tried the metal gasket on the headers for the heck of it and I could feel exhaust puffs between the gasket and flange...like said...do to that weird flange design. And I did properly tighten everything to and retightened after a heating and cooling cycle. But if others have better luck with the gasket I won't be against it. lol
