Ryan

I have a 1999 F350 crew cab, single rear wheel2 wheel drive---tow a 44 ft triple axle trailer at those speeds and will average 17-19 mpg-If we stay below about 76-77mph the fuel economy is good--if we run high enough that you can hear the fan clutch lock up the mpg will drop quite a bit-------------

Just seemed to me that the 7.3 would take all ford stuff and everything would be compatable--------