We've used Gear Vendors Under/Overdrive units ... or Browie boxes in those medium/heavy trucks, the Ranger Torque Splitter packs a 27-percent, 0.73:1 Overdrive ratio inside a heavy-duty aluminum ...

We could install a secondary gear splitter, like a Gear Vendors unit, or we could change out the rearend gears. In our case, the truck already features a 4L60E AOD transmission that has a 0.070 ...