I would not go to a gas engine for anything. I know of a lot of people who went from gas to diesel, and found out they had a top speed of 50 mph and the engine was tacked out. The gas would turn up to 5000 rpm and the diesel would turn 2100. You want to go the other way. What is the rear end ratio, what size tires, what is the rpm, these are all figured in when they built that diesel and put it into your truck. When Ford was building their big gas V8"s for their tandem trucks in the 60"s those engines would only turn up to 3600 rpm. and putting a diesel engine in would keep the truck from reaching over 50 mph. what a waste! There were reasons diesel engine came in to be the best choice, fuel economy(HUGH DIFFERENCE) compared to that 8 mpg of a 460 gas, and a longevity of 350,000 mile engine instead a 150,000 mile. I agree computers are doing it all now, but going backwards wont change that.