I am running a 250 with turbo 350 automatic, no overdrive, with a 3.08 gear and 235/75R15 radials. The truck weight is 3300 with two people and full load of fuel. I also have three small one barrels off of a Corvair. I can get 18 to 19 mpg at 65 mph and still have plenty of passing power. Rpm is in the 2400 range. I don't even have passing gear hooked up, just step on down and away you go! I say go for the 250, you will be happy, Joe
