[What's_nitro?]

I think as long as the body provides enough front downforce to keep the front wheels in contact with the ground you'll be fine. 4wd can still spin-out if you have too much power, which you will, of course. The only other issue would be steering and that's where the downforce would come into play. Besides, the power going to only 2 wheels will be more efficient and thus give more speed. Ever wonder why AWD cars get bad mileage?