it might be worth it if you do the labor yourself. i don't know if you're 4x4, but 3.73 would be as high as you could go if you are. if you're just 2wd, you can go down to i think a 3.08 gear. 3.55 would be fine with a low to the ground 2wd truck. i would spend my money on something else. I've had my gears changed, doesnt really affect mpg much. go too high and you have to rev it hard to get up to speed, go too low and your taching too high at freeway speeds