Opinions are like......
Skybum, I suggest getting your hands on a better rear end ratio. Tom of TC's Truck Parts has a few center sections that will work. Keep the alternator, swap the wheels for something a little more friendly and drive it. Dear ole Dad will be smiling from up above knowing that the truck is bringing you joy. As far as original, I am with Greg H. Having friends that worked at a GM dealer in the body shop, their greatest customer is GM's transit vendor. about 90% of the vehicles that arrive at most dealers need something replaced, repaired, cleaned, corrected, etc. So if that is the case, the term "original" only applies to the end of the assembly line prior to the TAA section of the plant (Test And Adjust)