2 points I really like about that block. The first, already pointed out, is the SBC motor mounts cast in. Something GM should had done with the LSX blocks from the factory knowing that they would become swap canadites and would have really helped selling crate motors even though they are sleep pretty good at night as it is. Second is the added head bolts, that was one of the LSX's weak links as the heads liked to lift when boost was present. I read about someones iron blocked LSX's that would lift the heads at the track and ballooned several radiators and they even ran blow off valves(yes you read that right) on the radiator hose to bleed off excess pressure when the heads did lift. That wasnt an issue with Gen 1 SBC's because of the 5 head bolts per cylinder vs the LSX's 4.