I'm going to have to disagree with 2.73's being the best gear for mileage. In my 85, I switched from 2.73's to 3.45's and gained 2mpg on the freeway from 22 to 24 on average. I once got 27mpg with my 3.45's. If you did happen to lose any mpg's with 3.73's it would not be much, like 1 or...