From what I have gleaned behind the rearend is really common and doesn't seem to be that big of a deal. . .never having driven a race truck before I can't comment on what a difference it makes or doesn't make in handling, but when I build my '79 F-150 I'm going to put the fuel cell behind the cab because it just seems to make more sense from a better balanced vehicle and a truck that will handle the same from beginning to end regardless of what the fuel level in the tank is. . .