Rule of thumb on the shims that most people use is one thick and one thin on the bottom. This basically gets the knuckle centered which is important for longer axle seal life. Then one thick and one thin on the top with the upper and lower knuckle torqued to spec, 71 ft lbs for stock studs, 100-110 ft lbs for ARP studs. Then take you scale reading. If it is high or low adjust by changing only the shims on the top.
Your trunnion bearings, birfield should be packed with grease. I do not put the amount of grease in the knuckle the FSM shows. That is done for a front end that will see a hundred thousand before it is opened up again. Most wheelers open them up a heck of a lot sooner then that, especially if it has stock birfs and locked diff and is wheeled.
One other thing, if your trunnion bearings are "no name" bearings, they are crap IMHO. I had one break on the street and take out a Longfield 30-spline. If the bearings came in a kit from a company with the letters T-G get some real bearings, better yet get Marlins 25 mm kit.
