I bought this engine from a guy last night and I think I got screwed. It's been a while since I've built a SBC and was on the lookout for a 4 bolt main block which I found on Facebook Marketplace. After cleaning some of the surface rust and oil off today, it looks like this block had been sleeved in every cylinder. Is this block any good or should I just chalk it up and look for another? Why would someone spend the time and money to sleeve all 8?