I work on a lot of rears in Fords, Chevy’s, Dodges, and whatever else. I personally never use grease mainly because it's messy and not really needed. When I installed cleaned bearings I put the inner one in dry, install the hub and than take a gear lube pump and hose to fill the bottom of the hub just full enough to let a little run out. I then install the outer bearing and put it together. After that I park the vehicle on a steep side hill each direction to let the fluid run out into the hubs from the differential. Then all you have to do is top off the differential and your good to go.
This is just my personal preference.