you need to determine a couple of things first.
rear springs and axles do not interchange between pickup chassis vs. commercial cab/chassis. How do you tell the difference? measure the frame width between the two trucks. pickup is roughly 38in outside to outside and the commercial chassis is roughly 35in outside to outside. the springs between the two are a completely different animal too. pickup springs are short and wide and the comm chassis is long and narrow. there is also a 4in difference between the two. commercial chassis has a distance of 60 in from the back of cab to the centerline of the axle and the pickup has 54in.
bottom line......
alot more info is needed between the two trucks before a determination of adaptability can be done.
