Also is it 2 or 4 wheel drive? If it's 4wd, how do the leaf spring bushings look? I have a 90 2wd and it's really squirrelly right now, I have the new upper ball joints to put in it, but have to get new lower control arms before doing the lowers.
It could be the rag joint as well. There should be a thread in the sticky about replacing it with a u-joint.