I liked the 3.55s in those trucks. Mine got better mileage and pulled better at 75 than at 70. Then my next truck with 4.10s got 2mpg better with a lift and 35s. The first was a 2wd. I doubt you'll be better off with 3.08s than 3.55s, seems the engine would be running below its powerband. The 4.10s are too low for those trucks. good luck