head gaskets
Thanks to all that answered.
To Zipper06 I'ved checked SCE Copper and their largest SBC Bore is 4.200" and Cometic MLS said the largest they can go is 4.230". Thanks anyway and to oneBadGMC I'm using head studs torqued at 80ftlbs as instructed. The Felpro gasket doesn't burn the ring out, it just starts loosing seal and lets combustion into the water jacket. But still running great at 5.70's in the 1/8 mile at 120MPH. I have checked the head studs & nuts and they stay torqued. The Felpro gaskets just weren't designed for this kind of abuse. I just change them and race on.
Thanks again.