I converted my son's 1978 CJ5 to 3 link front and 4 link rear last year with good results. I moved the front axle forward 4 inches and the rear axle back 6 inches for a better wheelbase, and 70mph on the highway is very stable. The only issue we have not addressed is that the Kings valving is way too stiff. My son lives 14 hours away, so I only have pictures of the build...he still needs to send me action shots. In addition, the jeep is driven the 14 hours to/from my shop, so very road worthy.
This next picture shows the track bar mounted behind the axle, which was necessary because the frame mount would not clear the drag link on extreme articulation if we mounted it in the front. (be prepared to articulate each axle about 50 times, as you will want to constantly check clearances during your build) We noodled this for a while before we mocked it up, as I was concerned the track bar would hit the third link. There wasn't any contact in articulation, but there wasn't much wiggle room either. The solution was to french the track bar about 1/4" at the potential contact point, so there is now plenty of room in all articulation configurations.
we built both axle bridges from scratch, which required a very slow welding process to ensure I didn't warp the housing.
The one wrinkle I didn't expect was with the exhaust. The headers were just below the bottom of the frame, which worked fine on the drivers side. However, on the passengers side, with two links, the header had to be shortened so it was above the top of the frame rail.
Here is the header prior to modification
Header after I shortened, but before it was cleaned up and painted.
Fitting the rest of the exhaust inside the frame rails with the 4 links in the rear required some pretty creative fabrication, but in the end, it works well and exits the jeep just below the frame rails in the rear.
This conversion took 3 months of nights and weekends. After driving, I would do another conversion. Next time, I want to use coils from a new JK instead of coil over shocks, and use a 3 link in the rear, as I think this will keep me from such heavy frame modifications in the rear. I essentially built a new frame in the rear to allow for the tall shock tower. The rear bumper is now part of the frame to keep everything aligned, and I added 2x3 tubing behind the shock tower that connected the rear bumper to the original frame rail.
Lots and lots of things to figure out in a conversion of this nature, but everything had a solution. We spent a lot of money on welding gas and wire, and over $200 on 4" grinding wheels to give everything a finished look. Quite frankly, it was easier to build my own chopper from scratch than it was to convert to coil over shocks, but it's all fabrication and design, so all fun.