Mickm, I don't agree. Apparently we have at least four instances on this forum alone. Statistically, when you consider how few people on this forum have a Hemi, then figure how many of those are using the MP aluminum head as opposed to the other brands. I suspect that it is a fairly significant anamoly, all things considered. If it were about wedge heads, the proportion would probably be less significant. I know that if there is a way to test these heads for this problem, I will tear down my engine in a heartbeat rather than chance carrying a 20K engine home in a steel sack! What heads are you running on your Hemi?