Caster goes down as lift height increases. To raise caster, you need to rotate the housing again. (lower the pinion). For control arms, this means:

Tilt the top of the housing back with Shorter Upper arms, or
Tilt the bottom of the housing forward with Longer Lower arms.

When only replacing one set, and depending on lift height, some mfg's upper arms may not adjust short enough to get the caster where you want it. Some people indicate that beefier lower arms hold up in the rocks better than stock arms. And when rotating only the top or bottom of the axle, pushing the bottom forward will (minimally) increase the wheelbase, as opposed to pulling the top back. So if you decide on replacing only one set of arms - front lowers are generally considered to be the better choice.

This is not an issue with the kit you are looking at - since it includes longer lower arms as well. In your case, the lowers will set the wheelbase, the adj uppers will be used to fine tune the caster and pinion angle.

 

[QUOTE This is not an issue with the kit you are looking at - since it includes longer lower arms as well. In your case, the lowers will set the wheelbase, the adj uppers will be used to fine tune the caster and pinion angle.[/QUOTE]

Based on your response, I better understand why this kit has placed the adjustable arms on the top. Thanks!

 

I ran the AEV brackets for three years and 6 trips to Moab. Yes I scraped them. No, they never broke off. I had absolutely no problems with them and they took the beating well.

Here's one side:





I just took them off a few weeks ago and went with Synergy fixed lowers simply because I'm changing things up.

 

My AEV brackets survived. Water tank not so much lol.

 

lol. You needed some of this.

 

bring it for next time