My 80 has about 115,000 miles on it, and that I know of, hasn't had any major repairs to the engine or tranny, except for a factory replaced radiator and starter. It looks completely stock, and like it has never left the road. The mpg is similar to what you all are getting (13/16). Except for a new vehicle, and I've owned a couple, this is the smoothest engine and transmission I've ever owned; but, it doesn't have kick-in-the-pants acceleration, and going uphill I was blown away by a little old chevy compact loaded with people and luggage. I just got this less than 2 month ago, and the oil is still golden, even after 2000 miles (Quaker State), the transmission shifts really nice, doesn't smell burnt, and the exhaust doesn't smell bad. Air filter looks good, too. In NM, we don't have inspections, so how many have cut their cats off with improved power/mpg, or is the motor just designed for a different powerband use, or is the truck just too heavy for the engine? Thanks.