Control Arms???

I dunno, I'd check the bushings in the upper control arm and pretty much leave them be if they aren't broken. Basically, the whole purpose of the lower control arms is to keep the axle from "walking", side to side movement under heavy cornering, and to keep the axle from rotating "axle windup" when you've got some serious grip. If you'll notice, we don't list any upper control arms on our site. Now the fox body guys had notoriously soft rubber bushings, so they'll commonly upgrade to the stock 94-04 upper control arms because they're significantly better than what they had, but if you're a 94-04 guy, you don't really have many options.

Most of our race customers opt out from uppers anyhow, and go with a torque arm, panhard bar, and even watts link setups, and with those components, you eliminate the need for upper control arms entirely since their purpose is being better done by something else. Heck, Griggs tells you to take it off if your racing sanctioning board rules permit it.

Point of my babbling is that if your rubber bushings are just fine, might as well just leave them there and spend that money on getting a quality lower control arm. Like quad shocks, the uppers are somewhat of a band-aid for a lousy performance design in the first place. Lowers are the ones you want and one of the major components in the suspension which will make a huge improvement.
 
Here's another option:

If you're not looking for 1.6-sec 60-foots and are not going to road race the car (that is, your KB installation is just to make the car a much quicker and more enjoyable street car) then consider staying with the stock arms.

I know, most people will think this is sacrilege but it stands to reason that if you don't need 9/10ths control of the rear axle as drag racers and road racers do, then acknowledge other requirements of the rear suspension design and stay stock. That is, the front bushings in the LCAs have a lot of play for a reason, primary among those is the fact that the geometry of the 4-link in the back needs it. Without this "give" in the bushings you risk binding things up and even possibly damaging sheetmetal mounting points.

I've got FRPP uppers on mine but didn't notice anything with them. The bushings are supposedly 50% stiffer than the OE GT bushings...but then again the OE UCA bushings are pretty stiff. If I had the option to do it again, I wouldn't bother. I might put some SFCs on the car to stiffen the chassis before worrying too much about compliance in the rear for a DD.

I've got 3.73s and a 9psi KB on mine with 245-tires and stock lowers and don't mind it a bit. NVH is near OE, ride quality is still there and the car still goes like stink. Really, I'd wait till you've got the KB on and decide after driving it a while if you just can't live without LCAs.