Two things I have learned about header installation over the years are first, to save gaskets, use a thing layer of high temp silicone sealer on both sides of the gaskets. If you can plug the small leaks, they will never grow into larger leaks which is the common gasket failure.
Second, I read from street rodders that they sprayed the inside of the header tubes with spray lithium grease on chrome headers to slow down the "blueing" effect. I tried the same thing on 2 sets of stock headers and was amazed at how long the factory paint survived. It is supposed to burn in and create some sort of protective coating. I can't say that I understand it, but I do believe that it works from my experience.
