Narrow Rear End

You need to purchase a jig. Mark Williams has a jig kit for about $425 you can buy. Unless you have a lathe it is easier to purchase the kit.

The jig has 5 parts to it; 2 bushings that fit tight in the housing ends, 2 bushings that bolt into the carrier bearing caps and a large heavy wall tube that slides thru the bushings. This puts the ends square and in line with the center of the carrier.

If you are going to make your own setup use aluminum because these parts need to fit tight and light surface rust will make it difficult to slide the jig together.