Just did a 93 F-350... . seems that whoever did the last brake job destroyed the l/s axle nut (left hand threads!!)and didn't bother fixing it or replacing the shoes on that side. Ended up having to CUT the nut into 2 pieces with a carbide burr to get the drum off.
I wasn't sure about the bearing preload either, I just tightened them up to zero last then gave them about 6 clicks preload. I'm sure that wasn't an exact FORD spec, but the truck is running fine!.