I finally had my new coils installed and the experiment is a success.
I have the 4" Superlift kit which has been great - zero problems. Once I added the GL4x4 winch bumper and a winch (about 200 pounds total), the front coils began to beg for mercy. I had a noticeable reduction in ground clearance with the front end, especially during steep descents when the weight would transfer forward. My original solution was to order a pair of 2-3" Old Man Emu coils to boost the front end back up. During the installation, it was discovered the new springs didn't work with the geometry of the Superlift kit and it boosted the front end an additional 4". Essentially, the front suspension was at full downward extension when sitting under the Jeep's weight. Phunkeydude experienced the exact same situation after he bought those springs from me
What we discovered was a coil needed to be cut off the OME springs, then the front end went together much better. Far as I know, he's happy with the springs now. The side effect of cutting a coil off a coil spring is you raise the spring rate, as there is now less material to take a given load. My goal was to get 2" of additional lift while keeping close to the stock spring rate (I liked the cadillac ride). I looked around for a spring fabricator and was eventually led to Deaver Suspension in Santa Ana, CA. I purchased a brand new OEM XK front coil spring (code SGZ, I think) from a dealer in Boulder, CO. I sent the spring to Deaver and asked them to exactly match the top and bottom of the spring so it would fit into the strut perfectly, and I told them I wanted a similar spring rate, but with the 2" of lift at the hub. They returned a pair of springs that looked identical to the stock spring except for slightly thicker wire (load carrying) and one more coil (to bring the spring rate back down).
OEM spring on the right, Deaver spring on the left...
The installed product brought the front end back up 2.25", exactly what I was hoping for. The ride is very close to stock, maybe just a touch stiffer.
The angles of the CV shafts, A-arms and balljoints all appear to be very similar to anyone running a 2" spacer lift.
Here's the upper control arm/balljoint angle before:
And after the new springs:
The upper balljoint angle looks a little dramatic compared to before, but because the coil is providing the lift and not a spacer, I still have the 'factory' downward travel limit provided by the strut. While I may upgrade to the custom UCA's for peace of mind, I'm not worried about the stockers. Several off-road trips have not brought up any issues.
One concern I had after receiving the new springs (with an additional coil) was whether or not the coils would bind on themselves during full compression. I flexed up the jeep yesterday enough to lift the rear tire off the ground, and there was still about 1/8" space between coils. No worries.
The blue bungee is holding the stabilizer bar up out of the way. It hasn't been connected since April - personal preference. The Jeep does lean over more than when it's connected but the ride is much better in my opinion. I'm not an aggressive driver so it's working for me.
So that's the experiment. The factory spring cost me about 80 bucks shipped. I then spent another 10 bucks to send it to California. The Deaver custom coils were just under 400 bucks, engineered, fabricated, and sent back to me (along with the OEM spring). If anyone is interested in contacting them, my guess is the cost would be something less than 400 bucks since they now have the specs on file. Though keep in mind these were engineered taking a winch and winch bumper into consideration. Without that weight, I'd probably be at about 6.5" of total front end lift. It's about 5.5" now. You can find Deaver Suspension on the web.