The real question is what is fast? Or what is underpowered? I do top out at about 50mph in my 48 F-5 dump weighing in at almost 7000lbs. I think a car should do 70 with ease, does everyone take their old car at run around at 70+mph all the time? Most of the time I see most of these vehicles sitting in garage, trailer, or at a show, which always makes me laugh at the "necessity" of the 350/350 combo for driving....when there isn't a lot of driving going on....