I'm running a Maxtrac 3/5 on my 21 2wd Elevation. If you're looking for a 3/5 I would look at kits with a notch. Maxtrac rides a bit rough in back imo, but that can be solved by running belltech shocks in back. Mine does come in contact with the shortened bump stops on harsh bumps, so I'll be notching the frame here shortly and adding the IHC helper bags. IHC makes a nice complete kit with helper bags, Belltech is solid as well and rides nice. I haven't dealt with Mcgaughys for a lowering kit, but had their 7-9" lift on my 2014 Sierra and was very happy with their service and the quality of product. What size wheels are you going with?