[Dave at Pelican Parts]

The safest course of action is to replace the engine. If the bottom end is known to be in excellent condition, you may be able to get away with just a top-end rebuild and chain replacement, but you are taking a chance that there isn't more damage than is obvious, or that you are putting stress on an already-worn bottom end.

If you are going to do the work yourself, it might be worth just trying the top-end. If you are paying someone else to do the work, it likely is not worth the risk.

--DD