OD secondary transmission

[brad k]

have an '06 with the g-56 transmission. the truck needs another gear bad when rolling around empty, even with 3. 73's. anyone know of a good OD transmission that can me married or unmarried to the stock transmission? wouldn't need it for 4x4, just for running around empty at 70 mph plus

 

[nickleinonen]

us gear or gear vendors aux OD unit?