That's what I'm not understanding. The shoulder is still there and it doesn't look deformed or scraped. Maybe it got hot and was forced out??? I have no clue honestly. Dads exploring options right now, he doesn't want to tear into it just for squirters so he's gonna go ahead with a full rebuild or look into an already build engine. If anyone can recommend a good place let me know, I don't have the time to rebuild it myself right now.