Originally Posted by 75F350

You are going to shop for a complete axle, drum to drum, or disc to disc.
If you shop for just a differential, you may end up with just a carrier, and you need a complete axle assembly. You could re-use your brakes and such, but in order to eliminate any set-up of gears, you need the complete assembly, housing and all. Then all you have to do is unbolt the springs from the u-bolts, remove the driveshaft, swap out the brakes (if you buy an axle without them) and bolt up the new one. Simple as that.