Looking to pull the trigger on a leveling kit and tires soon on my '15 sierra CCSB. Im sure this has been answered before, but would y'all recommend the RC 2.5" leveling kit or bilstein/rancho quick lifts? Also, what is the biggest size tire that you can run with each on stock 20's? I'm looking at 33x12.5x20s or 275/65r20s. With a true 33, how bad is the rubbing on the UCA/sway bar?