I am in need of "over 600hp" but will never consider putting a SLR engine in the car. Have you ever seen the price of that motor!!! I totalled out a SLR at work a couple years ago and the insurance company STILL wanted $250,000 for the complete(wrecked) car. In a perfect world I'd like to swap in a 2007+ SL55k motor since it starts off with 510hp(or 516......I can't remember) and can be easily modded to well over 600hp.