If you're planning on building a 1 ton 460 powered truck, why didn't you start with one? Due to the not so stellar fuel mileage they get, a mid to late 80's one can be had reasonably cheap.
A 700 horse engine is not going to be practial for anything but a race truck, and 12" of lift and other such things do not beget a race truck.

Not knowing what to do with suspension, and then all of a sudden having a 700 hp 460 smells of something, and it aint' pretty... Pitchfork anyone?