I am very slowly working on the oil consumption fix for my car, and the connecting rod bearings came out pretty bad. It was clearly starved for oil at some point. I have not taken a main cap off to see, but I was wondering how difficult it might be to roll some new bearings into it just for the peace of mind.Years ago I "rolled" new bearings in by just loosing the the main journals on the crank and removing one at a time. That was on a Chevy v8 . Not ideal but it can be done. Why do you think you need mains? If your new to this IMHO I wouldn't do it that way.