Cranking Up the Torsion Bars
 

I have a 6 in lift installed on my 99 sierra with the torsion bars cranked up on 1.5in. What are the Pros/cons of craking them up another 1.5in to there max?

Not too many bad effects, just a rougher ride. Probably should have the alignment checked afterwards though. I've heard of guys having tire wear issues after doing it and not having alignment checked.

Yeah your camber will change when you raise or lower but 1.5 inch wont affect it too much. More than that will require camber adjustment.