Jerry, those MPG's sound pretty good. I've had buddies with 02 7.3's that have hand calculated 26mpg running 75-85 on the high way. So some of the 7.3's do get great mileage. Usually that isn't the case. You're right, if I went with a 7.3 everything would have bolted in. But I'd have to purchase all those parts. Engine, trans, wiring harness, ECM, IDM, PCM, and fuel lines, and fuel sending unit. Plus, then I'd have another 7.3 to work on. Haha