Jerry has good advise on the about the cylinders. I would also add that I have had the best luck using cast rings and not chrome if you end up just putting in new rings. They seem to have a better chance of sealing up a worn engine.
If you read in the Chevrolet service manual they talk about adjusting the bearing clearance. I've found its more work to use shim stock but in the end you get a better job than using plastigauge. Seems that plastigauge usually leads to a bearing that is not tight enough.
