The GM NV4500 adapter to the Jeep Dana 20 is 5.875" in length. And the overall length of this transmission and adapter is 18.250". Adapter material is 356 T6 heat treated aluminum alloy. The adapter has a provision for a transmission mount. The adapter kit includes an adapter housing, 6 spline spud shaft, special large hole bearing retainer, sealed bearing, snap ring, set collar, gasket, seal, nylon lock nut, and adapter instructions.
Jeep Dana 18/20 transfer cases must have a 6 spline female drive gear. The transfer case bore size must be (4") large hole. The Dana 18 kit fits large hole transfer cases only. Transfer case shifter linkage will need to be modified in order to fit alongside the large 5 speed transmission case. Additional information can be obtained in our on-line catalog, Jeep & Scout Vehicle Section: Transfer Case Information, Jeeps 1974-79.
All transfer cases require the stock linkage to be modified for clearance on the NV4500 case.
The adapter kit is designed for exclusive use with a GM NV4500 4WD transmission. Several adapter kits require you to shorten the existing transmission main shaft while it is still in the transmission case. This is common when a 4WD GM NV4500 is being used. Each instruction sheet gives the exact cut off location. Also refer to the pictures:
GM NV4500 31 SPL. SECTION UNDER SLEEVE-3 GM NV4500 CUT OFF LOCATION-2 GM Output Cut Dampener Removal