I have a 1990 4-winns that is in real good shape. The engine overheated & I thought I blew a head gasket. The heads were checked, but when I reassembled the engine, I was having poor compression in cylinder 3. What is best, have this engine rebuilt, buy a short block, buy a long block, or part out the boat and get another. This is not the original engine. I am concerned with the OMC engine since parts arte getting scarce. Any suggestions would be greatly appreciated.