Re: lower the rear end ?
Both my Sy and Ty had 2" blocks in the back, never had any problems with them. Rode like crap since it bottomed out early, but never had any axle wrap issues under hard accel. Are you lowering a Sy or Ty? If it's a Ty you need to pull the "ELC" fuse to disable the air ride in the back and change the shocks. Sys don't have it, so nothing to worry about.