id let the machine shop install the new cam bearings after you get it hot tanked. also if your doing a full rebuild i really really would have it hot tanked because that will get ALL the sludge out of the oil galleries especially when they take a rifle brush through them after they do the hot tanking ( gets them nice and clean) which if you dont will bring this rebuilt to a nasty halt if some of that sludge gets into you bearing ( learned from experiance) and not fun to pull it out and redo everything lol