Re: Header help
I had the same problem with some headers on my last 454. I stacked a set of graphite-impregnated facing and a steel-expanded metal core gaskets. Exhaust manifold gaskets on head and header gasket on header. Gasket sandwich worked like a charm no more leaks. You still have to do the heat cycle tighten sequence like any header gasket but once that was done no more leaks. My headers were cheep junk.
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