I haven't seen anyone post about this but both of the blazers I have here (83 and a 78) have a crack on the passenger side engine cross member where it meets the frame. I've worked on 2 others that both had a crack in the same location so it's obviously a pretty common problem area. My 83 has been welded up at least once before me and the 78 is just a parts truck on it's way out but has never been fixed. If mine cracks again I'm going to try adding more bracing to prevent it from happening again. If you haven't checked yours it might be worth looking at. If yours is cracked too have you done anything to correct it? I'm looking for ideas.