so i figured out my problem today when i pulled off my front diff cover, 4 of the teeth sheared off one of the gears. now, i found a diff from a 90, 7.5 inch, but the truck had manual hubs, mine has ADD hubs. so this wouldnt work with my truck? not 100 percent sure

 

You can swap hubs easy, the diffs are basically the same, its the long shaft going to the drivers wheel that makes it "add" or not, and can also be changed out easy. So in the end, you can run which ever hubs you want.

What you should be more concerned with is making sure you get the right gear ratio.

Read here: http://www.brian894x4.com/Gearratiosanddiffs.html

 

yeah i know i have 4.10's but i dont really want to buy manual hubs either, so this diff wouldnt work for me because theres no place to mount that vaccum box or whatever its called right?