The GM TH350 adapter to the Dana 18 is a short 1.850”. And the overall length of transmission and adapter is 23.35”. The adapter material is 356 T-6 heat treated aluminum alloy and the adapter has a provision for a transmission. The adapter kit includes a adapter housing, new 4wd TH350 output shaft, 10 spline spud shaft, nylon bushing, bearing, snap ring, o-ring, seal, gasket, fastening hardware and adapter instruction.
This adapter assembly will fit any Dana Spicer 18 with a 10 tooth female drive gear. The transfer case index to the new adapter will require an index retainer & sealed bearing. Please I.D. the transfer case bore size (3-1/8”) small hole or (4”) large hole for proper retainer. Additional information can be obtained in our on-line catalog, Jeep & Scout Vehicle Section: Transfer Case Information, Jeeps 1941-79.
This adapter kit is designed for exclusive use with the 2wd GM TH350 automatic transmission. This GM automatic was commonly found stock in vehicles from 1969-81. It was used in both pickups and car applications. On 2wd transmissions, GM used three different tailhousing lengths. These lengths of the tailhousing are 6”, 9”, and 12”. The output shaft length corresponds with these tailhousing lengths.