Marlin,
If it only has 70,000 miles and 35,000 of those are on a "new" engine, transmission and radiator, I would be curious as to why it needed a new engine at 35,000 miles. A 350 Chevy is good for 4-5 times that mileage. Was it due to misuse, lack of routine maintenance, water/flood damage, etc? The answer may give you an idea about the condition of the rest of the truck.