getpsycho

Hi guys I bought my first GM Sierra a fews week ago. 2016 All-terrain and look to buy this kit. I almost read all the tread...but i'm french...so i think i probably miss somes infos... do i need to change my UCA if i set the shocks at the lower setting? I plan to fun 33" tires on my stock 20" wheel. Truck have the stamped UCA. I don't want to blow my ball joints. Thanks!