Jack, You have to have your heads O-ringed and reciever grooves cut into the deck surfaces of your block, in order to use copper head gaskets. But they never fail. With hi-RPM and/or with boost, the head will physically lift causing issues with any type of head gasket, EXCEPT for copper head gaskets with O-ringed heads and receiver grooves.
I run 6PSI of boost with upto a 150 shot of N20 and will bury the tach at 8,000RPM's... So I tend to push things to the extreem.
Check out SCE gaskets websites tech page on copper head gaskets.
