I did the same kit on my 2014 slt. (2/4 with spindles and leafs/shackles) Did you have to cut the bump stops? Mine is currently sitting on the bump stops and it bounces more than normal, not giving a smooth ride.
I had a question for anyone that can help out. I lowered my 2014 gmc sierra slt crew cab 2/4. 2" spindles in front and 2" shackles and 2" leafsprings in the rear. As of right now it rides a little bumpy even though im on a smooth street. I noticed that the bumpstops are sitting on the axel. Do I have to cut or remove the bumpstops. Thank you any info is appreciated.