440 source heads on a stock 440

I think Stealths are a good fit here. Just have a shop check them out before you bolt them on and I would replace the retainers and locks, or go for the upgrade when you order them. In regard to compression - I really don't think it will matter much. It's one thing if it's a yet-to-be-built engine but if something's done there's not much reason to re-do given the mild mannering it will have given the camshaft noted. I ran a cam 10° larger at .050 in a '76 used factory short block many years ago in a heavy E body. Drove it daily for two years: cold, snow, heat, pump fuel... Ran low 12s on GT Qualifiers. With a better head that engine will be stout.