I was figuring on picking up the specialty tool for the torsion bars... and the shackles are something I've dealt with before. I have a local guy who runs a repair shop in a 4 bay (2 wide x 2 deep) garage in his back yard if I get in over my head. Great prices for honest, competent work... but outsources for alignments (which I was aware of the need to do after the mod).
My understanding is that the Invalid Link Removed (or lift keys) allow for the torsion bars to be at the same load as stock height when in the lowered (or raised) stance. This should eliminate the 'rough ride' of tightening them to raise the nose. Am I wrong in that assumption? Also, I assume that loosening them to lower would make the truck sway and bounce more... right?
You probably wouldn't raise or lower it enough to notice a real change in ride quality, plus you're just changing the clocking of the bar, the load on it should remain pretty much the same. I raised the bars on my 95 and Wifey's 98 to offset the weight of the snow plow each has, and no noticeable difference in ride quality was noted on either.
The link that you have for those keys show they fit the 82-93 Blazer. I'm pretty sure that's for an S-10 Blazer, not a fullsize like you have. You would search for 88-98 K1500 for your truck.