The GM Muncie 4 speed adapter to the Jeep Dana 18/20 is 4.500” long. The adapter material is 356 T-6 heat treated aluminum alloy. The adapter has a provision for a rear transmission mount. The adapter kit will include a new main shaft for the Muncie, seals, gaskets, fastening hardware, & adapter instructions.
The adapter assembly fits the 1946-79 Jeep Dana 18 & 20. This kit is only offered in a 6 spline output shaft.
The GM Muncie M21 / M22 can be identified by an aluminum case that is 10” long and a side cover with 7 bolts. The new main shaft included in the adapter kit will fit all models 1963 to 1974. 1963 models will require additional parts.