This adapter kit will allow you to adapt the GM SM420 4 speed manual transmission to the Jeep Dana 300 transfer case. The adapter is 5.250” in length and is made from strong 356 T-6 heat treated aluminum alloy. We also supply a mounting provision on the bottom of the housing to use our heavy duty transmission mount (716021).
The adapter kit includes a adapter casting, spud shaft, snap ring, set collar, gaskets, fastening hardware, and adapter instructions.
Note: This adapter kit can also be used with the Jeep NP231.
The adapter assembly will fit the Jeep Dana 300. This transfer case was used in the 1980-’86 CJ-7 series. All 300s use a 23 spline female input shaft. Some of the adapters we manufacture include a new Dana 300 input with a different input spline. Therefore, if you obtain a Dana 300 from a salvage yard, please verify the input spline.
The adapter assembly will fit the Jeep NP231 transfer case with a 21spline input shaft. Introduced in 1988, the Jeep NP231 is a part-time transfer case became the standard for XJ and YJ models. It was also used in six cylinder ZJ models through 1995. Chain driven with a 2.72:1 low range, it’s reliable even with more than stock horsepower applied.