Norm,most of the 30+ pound boosted Ford Mod motor guys,use these multiple overhauls,and passes.. That's was the skinny on Ford /Turbostang's sites... However,appropriate fasteners(read : head studs,and the tensile strength gig,come into effect..) I won't plug a unfusible link,into a bomb.. I simply cannot afford high maintenance, & repair.. However,they are outstanding, they do need a certain maintenance, block/head surface prep,. They are worth every penny,in certain situations. ( I have read this,seen them installed on builds I have been involved with..Very minimum maintenance...Chevy exp..)