Hello folks, It's hard to believe but I first created my account during downtime at work 15 years ago and never posted. I don't have anything old enough to warrant being relevant in this forum, but I'm shooting to get a '57 in the future. Anyway, I thought I'd chime in with my experience rolling in some new bearings on a gen 1 Chevy 350, circa '84-ish block, two-bolt mains. I wouldn't normally even consider it, but it's not the most valuable engine and from some indications it's in pretty good shape internally and may be fairly low miles. So it's worth the effort to do the bearings "while I'm in there" replacing the intake manifold, exhaust, cleaning up the wiring, resealing the pan, etc. The big reason I'm doing it is I removed the rear main cap to do the rear main seal, and lo and behold, the lower bearing had a nice little groove in it, more than enough to catch a nail. It looked like a big piece of dirt fed in and just s****ed a path halfway across the shell. Wear overall didn't seem bad. Getting the upper shell out wasn't hard at all. I just used a cotter pin inserted in the oil feed hole on the crank, and spun the crank to allow the head of the cotter to push out the shell. Keep in mind I did plasti-gage the lower bearing and it checked in at a touch over .002". I haven't done the other ones yet, I'll probably get to them tomorrow. I can only speculate they'll be much easier than the rear main bearing primarily because they have no vertical surfaces to contend with. That I think made inserting the new the upper shell impossible it seemed until I loosened the other main caps to create a little play. Even then it was super tight, the task made more difficult by the crank wanting to walk rearward when spinning the engine, in essense tightening the little bit of gap for that vertical thrust surface of the bearing to fit in. So I'd have to pry it back forward, try holding it there while I simultaneously held the cotter in place and turned the crank. Here's a thread that gave me some hope: https://www.jalopyjournal.com/forum/threads/rolling-new-main-bearings-in.98554/ Good luck with all of your jalopies
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