I don't know exactly what was wrong with the 426s was, but as I mentioned, the main problem in the '70s -- and these were stock engines, mind you -- seemed to be that they went through spark plugs at an incredible rate. And I don't mean just having to re-gap and clean them, but having the tips burned so badly that they had to be replaced. Also, the carburetors simply wouldn't hold any type of adjustment. I don't know if that was the vibration, or what. And one other problem was getting them started in cold weather -- which can be a major problem in Iowa.

A couple guys I knew who bought cars with Hemis (one a Challenger, the other a Charger) got rid of them in less than a year, just because they were too much trouble.

Also, I should note that the cars I refer to were used daily, on the streets. Racing was a secondary occupation for them.