Re: Trail Tough or CSC
Trail Tough builds great stuff; you can't go wrong ordering from them.
As for as the YJ conversion kits go, part of the reason I went with the CSC kit was specifically because of the shackle reversal. It really makes it easy to allow a front tire to climb vertically up a rock without fighting the other tires' forward motion, and there's no worry about tweaking a spring due to forcing a front wheel rearward when coming up against a big rock. Plus, there is more clearance up front with the high shackle mount, as opposed to a low-hanging shackle.
I ran Missing Links up front for several years, and got kind of tire of that configuration. The Panhard Bar did a lot to improve its driving characteristics, making it essentially "invisible" on the road (i.e. it drives like there isn't the missing link "slop") and returning my sharp turning off-road in the rocks, but I was always banging those shackles against rocks and forcing the front wheels rearward when driving up against the big rocks, bending the springs in the process. I never destroyed a spring that way, but knowing my luck it was bound to happen sometime.
I've had the CSC kit for about 9 months now and I've beaten the living heck out of it. I've grown to love the shackle reversal up front, but I do recommend adapting a stock sway bar up front if you plan to do much street driving and don't have adjustable Rancho shocks. In back, I did manage to sag one 5-pack spring and "S" the other on the Rubicon while doing a wheelie, so a traction bar is also a recommendation for either the Canyon State or the Trail Tough kit.
You will love the simplicity and reliability of the YJ spring setup. You'll flex like a coil sprung kit, without any of the coil conversion's negatives. And no, the extreme length of these leaf springs have not caused any problems on-road or off. And you won't need a Panhard Bar with the CSC shackle reversal kit. I got rid of my Panhard Bar and haven't looked back.
Good luck with whichever kit you choose. The Trail Tough setup looks awesome, and the Canyon State kit is well-proven. And there shouldn't be much concern anymore with the delivery delays in getting the kit now, since Canyon State and AAPA seem to have solved that problem.
-- Geoff Beasley