Each vehicle does respond to lifting in different ways.
Typically, I do tell people that once you hit the 2-2.5’’ lift range, UCAs are a good idea. At 2.5’’, you start losing degrees of caster to the point that it may be difficult to get a proper alignment.
Many people to run a 2.5’’ to 3’’ lift without UCA replacement, but most do go with aftermarket UCAs. These help regain 3 to 4 degrees of caster, allowing the alignment techs to get you to stock or close to stock degrees of caster. You can always put the lift on and see if your alignment shop can get you sorted out. If they can’t get you rolling down the road with little or no wandering (due to caster), you can always come back for the UCAs.
We have 2 that are typically put on vehicles and this is my breakdown:
If you are lifting for esthetics and aren’t going to be running non-graded trail runs, the Light Racing/SPC UCAs work well.
If you do intend to flex out the vehicle more than a flat dirt road, I highly recommend the Total Chaos UCAs. All the Toytec rigs (employees’ rigs) run Total Chaos.