Frank, forgot about the gasket. been 5 years since I put the current one in, but it's a typical Victor Reinz composite with metal fire rings and a little molded line around the water jackets and bolt holes. No idea on the new or compressed thickness. But a typical gasket of that type would maybe be around .050 -.060 new and maybe compress .010-.015------ just guessing from previous forgotten Chevy adventures.

If you come up with a ballpark number on the strength/stretch characteristics of the bolt, please let me know - of course, I'm all in now.

I found the same bolt looseness on a JY head I bought a few yeas back.
Does this mean we all should have been going against all known convention and retorquing our heads periodically for the last 30 years? Or will my bolts all snap next week? Stay tuned, I'll keep my towing insurance current!

Driving over to ft Worth tomorrow - wish me luck.

Cheers,
DG