On my build on the 13 I put Zbroz 38 uppers for 16+ spindles last year because I didn't want to lose my older Evols and I think the 38 stance is better for the old bodywork. Those uppers worked perfect for the Riot spindles. A caster adjustment system for the upper A-arms may be the best option to develop as it allows you to set it to your riding preference. The Riot spindles are direct bolt on to the 16+ upper and lowers but tie rod ends need to be modified to clear lower control arms. I am keeping an eye on the movement on those spacers and bolts but a billet spacer that adds another bolt to spindle might be an option I will do to feel more comfortable with it. Spindles are cheap enough that it is worth playing around with as opposed to Elevate kit price. If I wreck a front end it is only factory parts I need to repair then,