[WarrenG]

I have 3.54 rear gears and the TKO600 0.64. 65 mph is about 1900 rpm, mileage between 20 and 21mpg. The engine cruises fine at that level and accelerates without loading up unless the pedal is suddenly floored. For "instant" (rarely needed) acceleration I downshift.

If I was to do it over again I would probably use 3.77's with the 0.64 or go with the 3.31's and the 0.82 OD for better response.