The output shafts on a 2wd and a 4wd are different lengths and possibly spline counts. Since you have both you may be able to swap the tailhousing and shaft from one to the other. A quick chat with the guys at a local tranny shop may give you the solid info you're looking for. Offer to buy the guys coffe and donuts to spend a few minutes explaining the differences. Being friendly will get you a long way and a lot of info... Chris