this motor,from what you tell me is a 75 350 2 bolt main 145 hp L-65 impala and chevelle 2 bbl. nobodys journal is exactly perfect on this matter and you would think gm would have kept better track but they didnt.the only way to know for sure if its 4 bolt main is to pull the pan.and if your machinist is no more familiar with the small block chevy i dont think id trust him to machine it.
