[dscott]

Agro1, In your case I would say yes. What surprises me is that the engine builder didn't take the time to have this engine dyno tested. To break an expensive engine in on a stand wouldn't satisfy me. When I sell a motor it is always dyno tested which allows us to break in the cam and rings properly, set timing curve for best results and tune carb. We have exhaust temp probes to tell us how the fuel mixture is at the entire rpm band. We know when a lean condition is happening.

The carb should have been retuned but this would only be necessary if a problem was found (pinging). Sounds like using the cheap gasket could have caused the problem. A good Fel-Pro and this problem probably would not have happened. With the cylinder pressure that a 12.5:1 motor makes any detonation would blow a cheap gasket. With detonation the cylinder pressure can increase 3 to 4 times over normal.

In my opinion the builder should have had this motor dynoed for his own safety. He should have used the proper gaskets. Then and only then would I have said "run it like you stole it". I think the builder should be required to assume any costs involved in the repair.
Don