Truck is suffering a typical air primer system leak. It'll run on it's own above about 1500 (can't verify, the tach cable is gone) but sounds about right. Now the really bad news, No high range in the transfer case. It'll move in low range but will not engage in high range at all. I'll check the linkage but you can feel the low, neutral, and high selections. Brakes work great as does power steering and it moved under it's own power around the bus turn around tonight and then made it's way back to the fence in reverse. Oil pressure is good, it builds air, brakes work but this truck is going to need some serious love. The cab is rusty in the usual parts, the cowl is pretty weak and it might need a transfer case. Dan, it will only need 2 batteries around this part of the country. The next step is to do an M900 series primer upgrade. Those old primer lines are a hard plastic line that is very prone to cracking from my experience.