1300 hours ain't bad. Should be at least 500-700 hours left in the bottom end. Cylinders seem to last about 600 or 700 hours on O-200's, so check to see when the last top overhaul was. If it's been over 600 hours, it'll probably need new jugs pretty soon. Some cylinders do make it to TBO, but it's rare, and they're totally worn out by then.
