How to Narrow an 8 3/4 Rear End

Bakerlite said
Wouldn't it be nice if you could get these for your Mopar
http://www.speedwaymotors.com/9-Inch-Ford-Cut-to-Fit-Axle-with-Bearing,103772.html

I actually have seen those on E-bay for Mopar 8-3/4's a while back. Not sure if their still available now