My friend's 1989 pup blew the head gasket between #3 and #4 cylinder. He gave the truck to me and I decided to rebuilt the whole engine. I took the head to a shop to have it pressure test, replace valves and seals and shave. I put everything back with the delta cam. 2000 miles later the head cracked on the exhaust side around cylinder #4. I think the head was a number 3. I bought the AMC head and everything is fine 'til now. If you're thinking about rebuilding the old head, I would recommend just get an aftermarket head instead.