8 3/4 rebuil ?

First off it's made by Powertrax and its a all gear type unit that can convert a single track to a locker. I first learned about it on the TV show 2 Guys Garage. It takes the place of the side gears to give both wheels equal traction with no slippage, but will allow one wheel to slip around going around corners like a limited slip does. For more details go to Powertrax.com and they list all the different kinds that they make. Even some for off road use or all out racing.