alrighty i have a 04 f-150, and its currently getting a 6 inch lift kit, im also putting 35x12.50 mickey thompson tires on it, i dont ever tow anything just the occasional mud hole and highway drivin, im in the military so most of my driving is on post but i occasionaly drive home to mississippi. i know it will have a little less power but i need to know if i nees to swap out the gears while its still in the shop, and also what gears shold i go with

 

I just went through the same thing and from everything I read and asked people here I decided to go with 4.56 Yukon gears. I would like to tell you how great they are but it is still in the shop! The guy at Randy's ring and Pinion said that with the new gears I would be running 1800RPM @ 60MPH and 2100RPM at 70MPH. (I am running 35 BFG's too). Good luck!

 

What gears do you currently have? Most people here would say that OEM 3.73 gears would be OK but a tuner would be needed to regain some power and correct for the increased tire diameter (spedo correction). If you have anything other than 3.73 I'de recommend upgrading to 4.56 gears with your 35 inch tire.