[LS short box]

Just FYI a car buddy of mine bought a super low mileage 6.0 iron block that had a broken oil pan. He put it in his 71 Nova. Ran great but it had a oil leak that he assumed it must be the rear seal. So we yanked the trans and put in a new rear seal. Still leaked. We pulled the trans and fly wheel and just cranked the engine over. Quickly saw the block was cracked near the two long small diameter oil pan bolts that go into the block. There is a oil passage that must not have a lot "meat" near the threaded bolt hole. Not saying you will have a problem but I would closely inspect that area. The salvage yard he bought it from really stood and bought a new chev block for him and he swapped all the parts over.