Here are the parts you will need for the conversion:
*early complete differential with axles (don't forget the shock attachment ears)
* early style straight pan hard bar
*pre 78 back half of drive shaft (or not)
The most common gear ratio was 4.30 we found a 4.10 which is a little closer to the original 3.90 her spicer style diff came with.
You just unbolt everything and carefully slide out the old unit, her springs were cut so no need to compress them, and the brake lines will move out of the way after cutting the wire tape that attaches them to the housing. You don't have to undo any brake lines.
Fill the diff with oil while it's out we used 80-90 EP oil, about 3-4 pints or until it runs out the fill up hole.
We opted to use the original drive shaft which is about 10mm too short, just loosen the drive shaft center support bracket and slot the holes a little then tighten the rear drive shaft to the diff then tighten the center support bracket. It's about a three hour job if you have two monkeys working together.
Photos shall follow.