If you are looking for pulling power, none of the Detroit 2 cycles were known for pulling power. They derived their horse power from rpm's. Thats why they were called screaming jimmies or later Yamahas. Until the late 70's there were many gasoline powered truck tractors with saddle tanks. I drove a gas powered GMC until 1968 and never gave it a second thought. I think the movies put a fear into people about gasoline explosions. With our over the road bulk hauling trucks there is no substitute for Diesel power. We have them set at 1450 ft. lbs. torque out of an 11 liter engine. But I would never convert a old bob tail to diesel unless it was one of those things that I wanted to say "I did it"
