Devcon Epoxy Steel- - - - -it can even be drilled and tapped in some applications. It's also possible to machine the top of the block for a stainless steel O ring made from .032" diameter aircraft safety wire, which is usually used with a solid copper head gasket for blower-equipped tractor pull engines. I've done that on several MOPAR hemi engines for a friend's unlimited class pull truck.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!