Yes you are correct. I thought it was a simple as moving leaf perches, but to be honest I would have to go back and look what we have done in the past. Like I mentioned, probably more hassle than its worth when you can grab a set of gears, driop it off and have it back the same day.

 

The OBS S/D has a Dana 80, gears and quite a few differentials are readily available.
Swapping the diff to F350 stuff is a big downgrade, the 450/SD is 10 lug with nice big disc brakes.

 

For a good quality dial gauge, and magnetic stand you are looking at a decent chunk of money to set the back lash yourself.

If your anything like me, I hate replacing things so I generally pay some serious $$$. The last digital caliper I bought cost 700 bucks, but I can pass that bad boy down to my child and it will still be as good as the day it came out of the box because it was carbide faced for ID and OD (I bought it when I was a machinist)