Advantages of aftermarket upper:lower control arms
Here is an example of the cut required for PST upper control arms.
Wrong question. The biggest advantage to tubular UCA's is the additional adjustment. If you're running radial tires you want more caster than what the factory parts can get you. Even with stock UCA's and the offset UCA's bushings installed for maximum caster, about the most you can get for caster is +3.5°. Which is still a pretty small caster number, especially for a power steering car. +5° caster will dramatically improve the stability of the car, and you won't get that without tubular UCA's because of the additional caster most of them have built in.
As for cutting, if the UCA has a tight "V" shape some clearancing might be necessary. Both the Firm Feel and QA1 UCA's should fit without this. Non-adjustable PST and Magnumforce UCA's, as well as some others, will require a little cutting on the mount, shown here. It doesn't effect the strength any, just a cosmetic change
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I would avoid heims at the UCA for a street car. Running a set like that on my Challenger on the street I was only able to get about 7 to 10k miles out of a set of heims before they needed replacing. I try to stay with bushings at the UCA.
Tubular LCA's don't do much. A boxing plate on a set of factory LCA's will dramatically improve things, especially if you take the play out of them before you weld the boxing plate on. Jim Lusk has a great video on this
One advantage to the QA1 tubular UCA's used to be that they added about 1" of suspension travel back into the suspension for a lowered car. The recent redesign to add a bump stop removed this advantage, although, if you have a seriously lowered car you can still remove the bump stop they added and gain back that clearance.
Adjustable strut rods are absolutely necessary if you use poly or Delrin LCA bushings. The factory length strut rods WILL be the wrong length. And regardless, the factory strut rods build additional binding in to the suspension that you can eliminate with an adjustable strut rod. Unlike heims at the UCA, I've had great luck with heims at the strut rods, the set on my Challenger has done 70k miles and it still nice and tight. If you have rubber LCA bushings the factory strut rods are ok, but for anything other than a cruiser there are advantages to using adjustable strut rods.
Here is an example of the cut required for PST upper control arms.
