[yamazee]

I can only tell you about the 392, I have the same motor in my backdraft, with the same heads and HP rating. Last night I was coming home from the car show here locally, and my friend was in his AMG SL55 benz. Its a brand new 2007, rated at about 600HP, it is very fast,,,,,,not fast enough though. My little cobra was neck and neck with his $200,000.00 benz, I got to the light laghing my ass off. I spent 40grand, vs his 200grand, and he could not pull away from me at all, even at 120mph he still could not pull away from me. I would say that the 392 is more than enough, especially for street use.