80 over isn't necessarily a bad thing, as long as the cylinders are smooth and not tapered. The more important concern is the piston-to-cylinder clearance. At one time we used long feeler gauge blades to check piston skirt clearance- - - -now it's more commonly done with a dial bore gauge in the cylinder and a micrometer to measure piston skirt diameter. Skirt clearance of .003" or less is a good thing- - - -very little piston slap, and the rings stay in good contact with the cylinder walls. If the piston fit is a little loose, it's possible to chuck the piston in a lathe and run a knurl on the skirt in 2 or 3 places. I've expanded pistons up to .003" or so by knurling and it really quiets one down that has noticeable piston slap before the rebuild.

Find a better-condition block if possible, but don't give up on the old one just because it's been bored, as long as it can be rehabbed otherwise.
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!