2bolt Chevy 350 or 4 bolt Chevy 350?

If you can get your hands on a 4 bolt main 350 that would be the better of the two. If all you have is the 2 bolt main, you can have a machine shop drill the holes out for you. That might cost a pretty penny. I built a 2 bolt main 350 for my mud truck i went all out with it heads, bored .30 over, 750 double pumper holly carb. ect. I never had a problem with it!