I thought about doing this myself as well. I changed my mind though when I saw what I was getting into. I found a good off road racing shop that installed the new gearing I provided for $100 per diff. I removed the diffs and brought them to them however. It would have been more if I just dropped off the truck. It's a bit tricky to get the torque and shim stack right and it's a one shot deal if you don't get it right. You have to start over with a new crush sleeve. There are threads here in the forum, I'm sure someone will give you a link. I bought the gears and the install kits online.