I have a 2001 Limited with 33" tires and the 5-speed A/T.

I'm looking for information on regearing the differentials to get back to the standard drive ratio with the larger tires. I just started pulling a trailer and with the extra weight I cannot keep it in 5th gear and I'm getting around 10-11 mpg. <img src="/forums/images/graemlins/frown.gif" alt="" />

According to the OEM service manual the rear diff is 4.3 and the front is 4.3 for the 4-speed transmission and 4.9 for the 5-speed; however, I beginning to think that's a misprint and that I have 4.3 in both the front and rear.

Also, I have the LSD in the rear, but would want to convert to the OEM locker if buying a salvaged diff turns out to be feasible (I don't know how hard this would be to retrofit given the wiring, switches, etc).

Does anyone know if simply buying the 4.9 gears is possible and whether they would fit my diffs? Are there other 3rd party options for the Gen III trucks?

Any help or advise would be most appreciated.

Thank you,

Tony