The Cruiser Crawler box was obtained from Mark's Adapters in Australia. Details can be obtained from this web site. http://www.marks4wd.com/Cruiser-Crawler.htm
The Crawler box is either a 1:1 ratio or a 3.05:1 ratio. The box bolts to the back of the transfer case and effectively changes the speed of the input shaft before it gets to the center diff on the transfer case. The advantage of this system is that it does not move the transfer case and the drive shafts remain unchanged. However the system does require modifications of the floor board and the gas tank. We installed it in out ShortBus that was already fitted with a 2" body lift and the gas tank was re-located.
Below is a brief explanation of the system and some installation photo's. This is by no means a detailed overview and there are quite a number of installation steps that are not listed.
Installation requires the removal of the transfer case and then splitting of the case. The rear tail housing is removed first.
The new input shaft is installed in the case. Essentially the input shaft goes into the Crawler box, where the ratio can be changed and then it is fed back out on the coupler that surrounds the input shaft. This coupler is attached to the gear that drives the rest of the transfer case.
Once the new input shaft is installed, the transfer case is re-assembled and then the adapter ring is installed. The couplers and bearings are installed and the Crawler is mated to the transfer case.