This adapter kit will adapt the reduction housing of the GM NP203 to a Land Cruiser 10 spline transfer case. The adapter length is 1.525” in length and is made from 356 T-6 heat treated aluminum alloy. The adapter kit includes an adapting casting, NP203 to Landcruiser output shaft, vent assembly, sealed bearing, gasket, fastening hardware, and adapter instructions.
This adapter assembly fits 1963-73 10 spline transfer cases. The drive gear has 10 internal splines and a diameter of 1.375”. There cases are equipped with a vacuum style shifter.
The NP203 originally coupled to the GM SM465, TH400, and TH350.This full-time, cast iron case is made up of 4 housings. It is a chain-driven case with a front housing using helical cut gears offer a 2 to 1 gear ratio. This assembly was used in 1971-79 vehicles.
By using the 2:1 reduction portion of the NP203 GM transfer case, we have designed an adapter kit to put this reduction portion in front of both the 10 & 16 spline Land Cruiser transfer cases. This kit will only work with GM transmissions that were originally coupled to a NP203. These transmissions would include the TH350, TH400, SM465, or a 700R when using our P/N 50-6900 (with the modified 700R output shaft).
The assembly length of the crawler box is approximately 7” long. A normal installation will require crossmember and floorboard modifications. Due to the length of this low gear box, your engine location may need to be adjusted further forward than normal. We have had some customers adjust their rear axle location to compensate for this extra length. The kit comes with an adapter housing that couples the NP203 gear box to the Land Cruiser transfer case, and a special output shaft. The shifter linkage for both the transfer case and the NP203 gear box will need to be fabricated.