ford 2.3's rock!!! got turbo? :clappy:
TJ coils seem to make sense but i'm really annoyed with how secretive all the aftermarket joints can be with the actual spring rates and whether or not they're linear or variable rate.
no experience with anythong other than stock on the TJ's but i'm hearing that full-traction springs tend to run a bit soft so you may want to check those out if you look at aftermarket. OME would be the #2 choice i'd point you to, but the tech needs to be familiar with the product line.
the big question is - how much latitude do you have in deciding where to place an upper spring buckets? you want a tall springs with more wraps than average to run a 3-link. do not be lame and leave either the lower or uppger spring un-retained on the perches!
in my experiences with the rovers, it seemed like the lower mounts always took the worse beatings. i think we got it perfected with this little recipe here:
get a 1" aluminum disc in the same outside diameter of your spring, and have the outside edge stepped down .5" so that the spring is positively located on a lip on the lower perch. to mount it to the axle, weld on a U shaped tab and run a bolt through the center of the mount. you'll then want to capture the lower spring with a retainer of some kind. sandwich the mount with two pieces of .25" flat stock and run it wider than the diameter of the spring. you want the clamping bolts just past the outside of the spring to keep the bar from deforming. this takes a bit of work to fit around the rise of the coil on one side but is doable. Using a spacer / sleeve between the flat stock is a good idea to keep from bending the bars at the ends. the bolt through the center will pull the middle together and keep it strong. if you want to get fancy you could also have channels for the retainer machined into the bottom and top surfaces of the mount to the retaining bars are positively located and don't try to twist against one another.
if you want to be adventurous, FJ80 front coils and Land Rover coils are about the same diameter and would give you good selection. FJ80 coils are taller than rover springs, but the rover springs are softer.
RoverTym.com makes their own coils in a variety of lenghts and is completely open-book with rates / specs. they have a 189lb/in linear coil that would probably work very well. they're slightly larger than a TJ coil diameter wise so you might have to think about the upper perch just a bit.
just some food for thought -