Oil Light Popping On

Anything lower than 20lbs hot and I'd put in new bearings. If you do it at that point, you might get away with just new bearing shells. If you wait until it's down to 10 lbs, you're probably through the babbit and into the backing. Once it gets to that point, you'll probably need to turn the crank. You also risk the chance of spinning a bearing or throwing a rod if you put it under a load in that condition.