Petroworks GRS II "SUMO" Gears makes your Transfer Case 115% lower than stock in low-range and 18% lower than stock in high-range.
With stock ring & pinion gears (3.72:1), the G.R.S. II (Gear Reduction System) gives you a final drive ratio of 66:1.
These gears were developed specifically to recover lost power when adding 31" tires.
These are "Sumo Gears" which are made by the same Japanese manufacturer as the OEM Transfer Case Gears. They are the main supplier of aftermarket gears to the US Market. They were based and designed and built from the gears that Petroworks originally built in the early/mid 1990's.
(x1) Set of new GRS II 4.89 gears
(x2) Countershaft Needle Bearings
(x1) Countershaft O Ring
(x2) Large Seals
(x1) Small Seal
(x1) Shifter Sheet (Petroworks Polyurethane Shifter Sheet)
(x2) Thrust washers
(x1) Large Case Gasket
(x1) Small Case Gasket