That was an excellent reply. Every informative!
I wiĺl leave sway bars alone.
I have bought the street boss springs and they will be here next week. If the springs and the orange give me what I want, then great! If not, then I go to yellows.

Glad to help. Let us know how it works out. I'm curious of your thoughts on your new setup.

Konis are on order and i have the boss springs already (cheap).

I also wanted to take care of a groaning / creaking sound that I figure are the bushings, but ford says the bushings are not serviceable except for the sway bars.

now I don't know exactly where the groaning is coming from, but my service department has a set of rear Shelby control arms for $100 that are take offs.

this a way to go for me?

Soo...
no one can tell me if the rear lca on the Boss , LS or Shelby are stiffer?

I like the idea if polyurethane, but don't feel like greasing them .

If your looking for non grease lca's.. You might be interested in these..

https://www.cheperformance.com/pages...l-arm-bushings

https://www.americanmuscle.com/white...-lca-0514.html

My brembo car had the same lca's as the Shelby. They are supposed to use a higher durometer rubber in the bushings than the stock GT units, but are heavy and not nearly as stiff as poly. I ended up replacing mine with a billet aluminum set from Steeda to reduce wheel hop. I greased them with Mobil 1 synthetic grease when I put them in nearly 2 years ago and haven't touched them since and don't notice any squeaking yet.

I left my control arms alone. After the steeda sports, koni yellows and steeda adjustable PH bar my rear axle never once hoped again. And I like it this way :metal:

Did the OP ever report on his new setup?

The Boss springs are only about 25 lbs/in stiffer than OE GT (123 vs. 148 in front), so they're probably a good match for the STR.T/Orange Koni. In fact, the increase/drop on those springs is so mild that any difference he feels is likely to be mostly from the new struts, rather than the spring.

Yes, I have the springs and the yellows on there. I love it. Next I want to get a stiffer front sway bar.

Hey Jim, would love to see more in terms of what your thoughts are with your new setup. Sounds like you might take the sway bar plunge too.

It certainly feels stiffer, which is what I wanted. The front is turned to 3/4 stiff while the back is 1/4 stiff. I discovered that the back too stiff makes it bounce.

and yes, I want stiffer roll bars to reduce roll