Marlin
http://www.marlincrawler.com/differential/completeAs already stated they cannot be used in the rear.
Be careful about disc brakes, most of the kits out there use a solid mounted caliper and that can cause problems on a semi-float rear axle (Toyota). No matter what you do there is some movement in the axle which causes the caliper to open up and you have to pump the brakes to get pedal. Mine only does it on the trail and not the street.
What these kits need is a floating caliper. Golden State Motorsports has come out with a kit that has a floating caliper and are in the developement of an e-brake for it. I have seen these kits in person and in use on the trail and they work flawless, no pumping.
you can check them out here.
http://www.pirate4x4.com/forum/showthread.php?t=1034855&highlight=golden+state+motorsports
