8 3/4 Assembly??

Here are some links that have a lot of information

http://www.pirate4x4.com/tech/billavista/Gear_Setup/

http://www.mopar1.us/backlash.html

http://www.mopar1.us/setuprear.html

http://www.mopar1.us/875rear.html

And here's a page with all kinds of information about an 8-3/4

http://www.moparts.org/Tech/Archive/axle.html

Other than this you might see if you can find a factory service manual.