I currently have the 3.55 gears in my 99 F150 XLT ext. cab 4x2. I like to offroad and want to put in the limited slip rear axle. I was wondering if ford can do this and how much it would cost. Also I have 255/70/16 Wranler AP tires on it but would also like those to be bigger. Any help is greatly appreciated.

 

I priced it several months back from a shop that specializes in standard shift transmissions and differentials, they quoted $800 for the parts and labor (this included a ring and pinion as well). If you use your current ring and pinion over, the cost would be slightly less. I would surmise if done by Ford, the cost would be considerably higher. The outside shop was using a Traction Lok differential, so it would be covered by your basic warranty.