head gasket thickness??

I'm in southwest va about 2hrs from martinsville. There is a few members from that way I talked to a guy the other day from martinsville. My wife has family from there but iv never been myself.
My 318 is a 86 I'm doing 302 heads as well home port job 340 Intake luniti voodoo cam headers and if I can get the money a street demon carb. I have a 4160 holley if not. I'd like to rebuild the bottom but just dont have the money and the engine ran strong when it was in my truck so I know its not hurt. Its going in a 75 dart swinger soon hoping to have it together by fall.