I finally bit the bullet and decided to replace the infamous intermediate steering shaft on my truck. The 1999-2007 trucks had an ongoing issue that apparantly GM couldn't figure out how to fix but they kept on making them with the poor design. When I had mine in when it was still under warranty the fix at that time was to pull it and grease it. Well that "fix" finally got so bad I decided to replace the whole thing. GM came out with an updated shaft in 2007 or so (GM part #19153614) that is sealed, and from most accounts seems to fix the issue. I also replaced the column bearing (GM part #88963617) with an updated design as well as I was having issues with it leaking and causing noise up by the steering wheel. I got both parts shipped to my house for about $95. The repair is fairly straightforward as there are only 2 bolts to actually undo. You just have to be careful and make sure that you don't allow the steering wheel to turn much as apparantly you can cause an issue with the clock spring if it goes too far. I just bungied it in place to keep it stationary. The entire repair took me about an hour (just like you estimated airjer). I didn't get any pictures under the dash because it's pretty tight under there (or under the hood because I was too lazy), but I did take pics of the old/new parts.
Picture of the old shaft/bearing
After taking it for a test drive with the new parts, it is like I'm driving a new truck again. The vibration in the steering wheel is gone, and no more rubbing or noise on the steering wheel. I have to learn to keep my mouth shut about not having to do many repairs on my truck though because since I've said that I've had to replace the HVAC blend door, water pump, and now the steering shaft. Hopefully I've met my quota for awhile
At least I've been able to do them all myself for the cost of parts.