Uh-Oh. An opinionated novel...
I prefer a 2" drop spindle. Doesn't mess with any of the front end geometry. With those, the suspension is essentially still stock with the exception of the spindle being moved up 2".
...and a 2" drop spring.
This spreads the drop over 2 components equally.
Problem with that is, I just don't like aftermarket drop springs.
While the gauge of the drop spring looks heavier, in reality, all they do is mimic the OEM grampa's-soft-recliner ride. Not what's needed with a now somewhat limited suspension travel.
My preference is to cut the stock spring.
1 coil = 2" of drop.
Cutting the spring increases the spring rate.
Some will disagree with cutting springs.
But, customizers & HotRodders, from big budget 'Big Name' guys to minimal budget backyarders, have been doing so since the '40's when the first coil suspensions became common OEM, right up until today with no ill effects.
That being said, cutting more than 1 coil is not a good idea.
Lowering LCA's come with urethane bushings. That means the uppers should have urethane bushings installed as well.
Original OEM soft rubber upper bushings combined with stiff new urethane lowers is going to beat the cr*p outa the uppers due to their softer durometer.
They are also more than a bit of a PitA to install. I had to use (borrowed time) a mondo-HUGE press to get the one's in my truck's UCA's.
IMO, any single front end part that lowers 3" is a bit extreme for the suspension's design. Makes for difficultly with alignments. Funky handling characteristics.
If you're set on 3" drop control arms, a 3" drop UCA/LCA's combo will spread the drop over 2 components. 50/50 instead of all-in-one.
Besides spreading the drop over 2 components, an advantage with a UCA/LCA combo is that many of those are designed to move the the wheel one inch forward inside the well.
What this does is help to reduce, (eliminate?) that annoying tire rub at the bottom rear of the wheel well/firewall on hard suspension compressions or when tight turning over stuff like speed bumps or steep-ish driveways. Some parking lot entrances/exits.
Yup. A bit more $$$.
To get to 4", the expense of the uppers & lowers can be recouped via...cut springs.
To get down to 4" with the 3" drop UCA/LCA combo?
Cut 1/2 a coil
Now, the drop is spread out evenly, near equally, over several components, each with minimal geometric alteration from the OEM spec.
The UCA/LCA/.5 coil cut = 1.5"/1.5"/1"
As opposed to the drop LCA/short spring combo of 3"/1".
...and with a spring that's just, well...'adequate'.
Yea, the combo will LOOK good, but what's it going to be like to drive?
May have to deal with alignment specs that are close.
Close but no cigar. Good enough is not good.
Could be O.K. Could be a bit of a bear.
Could it be daily'd? Long distance driven? Comfortably, with confidence?
This is what happens with lowering methods that are somewhat out of the norm.
The not-so-common with questions attached as opposed to the tried-n-true with a proven history.
But like I said. My opinion.
Love the color-matched mirrors! Looks so good on these trucks while being so uncommon at the the same time.