[SCOTI]

The rear end will work /upgrades (posi, axles, etc). If you get 'serious' about putting the power/torque of that big-block to the ground vs the easily achieveable smoke show, there might be a need to upgrade the housing (the truck arms will still get the job done).

Set the motor back as far as possible in the chassis & utilize as much 'light' stuff as possible to help w/the weight of things. Fiberglass items, alum radiator/water pump/intake, gear reduction starter, wheels, relocating the batt to the rear of the truck can all make an impact.

For seating, look into 88-94 GM truck low back buckets (or split bench). the seat backs on these are fairly thin yet still comfortable.