5-spd here with 3.73's and there is nothing wrong with that combo. With a 245/75/16 tire, I'm spinning like 2200-2300rpm at 70 on the freeway. Dropping to 4th pulls me up to 3k which is about where the little 4.8 starts to pull anyway, so I like how the gearing is. I still get 21ish mpg on the freeway if the trip is long enough. The 3.73's make in town driving decently entertaining as it helps the truck to squirt around in the lower gears pretty well. I'd do 3.73's or 4.10's in a heartbeat if I were you.