top gunz rear spring spacers go on the top of the spring as well, but are have a hole through the center for the airbag line.

 

well most lifts i was looking for were doing 4" drop knuckles in back and 2.5" progressive rate springs in the rear instead of spacers, would the average air bag be tall enough to compensate for the 2" height change?

 

You could probably fabricate a 2" spacer with a hole in the middle to put at the top and that would probably work, i know airlift had about a 2" spacer when they had their shorter bags but now have an updated longer bag not requiring that spacer. Get one made out of teflon or something.

If you don't put a 2" spacer then the truck would probably sag 2" until the bag would be effective.

 

Alright thanks for the info guys