If you go with an engine and transmission out of a 70 or 80s Chevy/GMC truck then you will have the passenger side drop on the transfercase. A stock 350 with 700r4 or th400 auto or the stock manual transmission married to a NP 208 or if you get something older you might get the NP 205 married and then it's almost a drop in and go. Almost. Look for a donner truck in your area that fits the bill and you'll have everything you need.