I am interested in anyones' advice for replacing rear bearings, axle u-joints, pinion seal and a rear spring on an '84. Any special tools needed for these jobs or useful hints?

It's not to hard to do any of the parts your talking about. You start with taking the caliper off with removing two bolts on the back side which may be a torx bit bolt which they used on some that year. Then the rotor slips off but you have to have the parking brake off to do so since there is a second brake setup inside the rotor which is a mini brake drum setup. You should be able to unbolt the bearing hub through a hole in the hub that you can line up with all three bolt in the hub. Before you do any of this you have to take the center bolt off in the hub which will release the axle assembly. This will leave the brake assembly hanging there and then you can remove the inner universal joint next to the rear end and it will come out of the car where you will be able to replace the joints easier. The spring is pretty easy. All you have to do at this poin is unbolt the caps holding the spring in and remove it then you can put the new one in. . I have a 84 and have already done this and can tell you it will be a day project. I hope this helps