i am looking for an engine and trans to put into my 84 gmc 1500. i was wondering about gettin a wrecked salvage pickup with a 5.3 and 4l60E. i have doubts about being able to do the wiring myself. is the computer one unit for the engine and trans? is there an after market wiring harness i could use that would suit me better then trying to use the used harness? also would i have trouble finding a tranfer case that would work with this app. any knowledge on this subject would be greatly appreciated.