what gearing?

[blackbullitt]

i have a 2005 f350 with a 10 inch lift, 38'' mud grapplers and 20'' rockstars. i am going to size up to 40'' grapplers this winter. however would a 4.56 gear be the best to get me back around stock? i have 3.73 from factory. i would rather be a little lower than factory rather than being a little higher. but im afraid 4.88 would be too low. thanks for the help guys

[05powerstroke38/24s]

i think 4.56 will do i had them on my truck when it had 40s it seemed fine to me and i have them now with 38s

[HOTWHEELS34]

Yep, 4.56 gears

[Raul@Stealth Automotive]

tech speaking 4.88 is what will get you back into stock form.. but 4.56 will be a lil better and give you better MPG on the highway....