Kits are available for both the Dana 18 and Dana 20 transfer cases. These kits are shipped complete with the necessary hardware and gaskets to obtain the 3.15:1 low gear ratio. The Dana 20 kit fits transfer cases 1963 to 1979 in CJs, Jeepsters, Jeep trucks, Wagoneers, and 1972 to 1979 Scouts. This is a 5-gear low range kit replacing the stock 2.03:1 gears. A slight amount of internal case grinding is necessary.
Advance Adapters got its start in Downey, California in 1971 with a single adapter mating a Muncie car 4-speed to a Jeep Dana 18 transfer case. Eventually headers, overdrives, motor mounts and linkage brackets were added to the offerings to complement their core adapter components. When interest in rock crawling spiked in the mid-1990s, Advance Adapters offered low ratio transmission swaps then switched gears into the ultra-low gear transfer case arena. Today, the company is based in Paso Robles, California and their engine and transmission conversions for Jeeps are in kit form and sold as individual components. Shop Advance Adapters Now