i seem too remmber reading something about when you put on bigger tires you need too change your gear raito. now this is my issue is it the gears in the rear diff? and how do you changed them? and what do i change them too? i currently have a 2008 b4000 i am looking at a super lift 4 inch suspention lift, with 31 inch tires. i went too my local 4x4 shop and they have the lift for 1300 seems like a good deal too me. so any help with my questions would be great.