Xj leafs work quite well in yj set ups, I would imagine it would work with a tj too. Xj springs are non-symetrical, the center pin is offset to the front, you can rotate them front to back and it kicks your axle back to extend your wheel base. We did this recently to a friends yj and we were able to fab a rear bumper with shackle hangers mounted directly to the bumper. I am not certain of the wheel base now but I think it kicked the axle back about 8". I haven't done any research on tj leaf conversions but if I were to do it I think this is the method I would use. I don't think it would require an excessive amount of fab, spring hangers and shackle hangers, if you were to use stock xj springs you would want to spring over so you would probably want to fab an antiwrap bar. Mjs are sprung under so depending on the amount of lift you are running they would give you approx. 5" of lift over stock xj springs if you were to run them spring over.
