That’s the review I was looking for ! I guess some new UCA are in my future, thanks
I should probably mention that the reason I got the UCA's at first was because I had the 5100's with the stock springs and the seats at their highest 2.8" position. I've tried a ton of combinations on this truck because the work itself is easy for me, I have all the tools and generally my time is my own so it's an easy Saturday morning to completely change the suspension front and rear - the only hard part is that parts cost money.
The reason the arms were necessary with the stock springs and 2.8" lift is the alignment cams ran out of adjustment range so the alignment tech had to make some compromises to get it as close as possible. This was all several years ago but I think the result (with stock arms) was both sides got a tiny bit of positive camber, one got more than the other & caster was too low on both sides. It drove OKish but not great so I bought the lift-specific upper arms and got it realigned, still with the 2.8" setting on stock springs. That was just right to correct for the ride height difference on the alignment cams so they had enough range of motion to give a proper alignment without compromise and the truck handled well on the road - but with the 2.8" setting there's too much gradient between unloaded and loaded suspension so any time a front wheel left the pavement it felt like a bucking bronco or a pogo stick.
Between then and now I've made a number of other suspension changes not really related to this conversation exactly because a friend owns a 4wd outfitter and wanted me to try out a few prototype suspension projects he was going to be selling..
But after that I went to the 5100's front and rear, Eibach springs front and rear, and the front ones I just checked I did have them on the
bottom ring of the Bilsteins. That results in less net lift than I previously had both front and rear, but it works out really well for how i use the truck and how I drive.
I already had the upper control arms so they're still on there but I don't know how much they are really contributing to the handling. If you look at your alignment cams (all four sets) and see that any of them are maxed out (the eccentric cam is horizontally aligned) then chances are you'll benefit from lift specific upper arms.
