I`ve got tti headers on my car, I have reused the gaskets about 3-4 times , put hi heat silicone one the damaged part , let it dry , reinstalled . My exhaust system is full 3 1/2'' dumped , never had an exhaust leak yet.
Did the same on my 406 sbc , as long as u dont have much back pressure , and the flanges are smooth on the head side with no welded riings around the tubes , it has worked for me , hardly ever buy header gaskets.
