Originally Posted by Richard Gallant

@Discorama top hatted block so that is pretty unlikely, my gut is rockers or lifters oil pressure light on is always bad

Originally Posted by Discorama

When you rebuilt your engine, did you check for slipped liners? I found an imprint from what looks like a moving liner of cyl #4 on the head gasket. Since I had the typical knocking and this cylinder caused the engine to fail I believe it was indeed a slipped liner.