My truck had issues when I bought it 7-8 years ago but have steadily gotten worse. It seemed like the usual fixes didn't fix anything but the balance of my check book.
What was happening was death wobble during braking, death wobble on uneven rutted roads, shimmy between 45-55, and a basket ball bounce when slowing down.
Parts replaced, some more than once by assorted shops;
brake rotors
tie rod ends
lower king pins
tires
rims
shocks
steering box
cv joints
u joints
steering shaft
and added a steering stabizer
Non of which helped.
After I got my truck out of its icy winter grave (another story) I noticed some cracks. The front left leaf spring bracket had several cracks from one shop that air chiseled it off and reinstalled it with bolts. The right side was also loose. And a cracked steering box bracket. The leaf spring bushings were also shot but not in a way that was obvious. I suspected this to be the main problem some time back but no one would change the bushings.
I got it to a frame shop and they confirmed the problems. Once parts arrive, the plan is to repair or replace the leaf spring mounts, replace the leaf springs, replace the frame bushings, and replace the steering box bracket.
Sorry for the long thread but I hope this will give you more things to check if you run into similar issues.