I've been following the thread since near the beginning, & read the thread, and the definitive solution to this very common problem with GMT800's is not defined with a clear cut solution in this thread. Still looking for useful, constructive replies to my posts as well....however, it seems like there isn't a huge knowledge base here on this site. Perhaps need to look on GM Full Size or somewhere else like GM-Trucks.com, Z71 Tahoe Suburban, or other?
I quoted the post that gave the answer to your question.
This was the fix for the OP's specific problem:
In case anyone was wondering this is proper orientation for the center link. Tie rod droops are angled down and towards the rear.
It may not be the fix for your problem, but it is the fix for their problem.
On these vehicles all the front end components: inner and our tie rods, sway bar links and bushings, control arm bushings and ball joints, idler, pitman, wheel bearings, shocks, jounce stops likely need to be replaced at this time. Sometimes the steering box is the problem and needs to be tightened or replaced as well.
Any one of those items can cause this
type of issue. There is no one definitive fix for everyone. Start your own thread so that we can help you track down your particular issue.