340 block with NO main caps

That block will clean up. I've done way worse.

FABO member has complete sets of main caps for sale right here. They are 4 bolt caps, but you just cut off the outer bolts and run them.

I'd buy those long before I tried to find a set of used caps and screw with that. Then you need to get it line bored.

There is nothing there that bothers me for 50 bucks. You're going to need to bore anything you buy. And you SHOULD deck the block, but some guys are just too cheap.