There is a very lengthy thread about this on some other Jeep forums, (maybe there is one here, I just haven't seen it myself). There seems to be no exact answer. For instance putting "18" front springs from a JKUR in two different JK's yield different results. Sometimes it is because the JK had a "16" front spring vs. a "17" front spring, but some report both Jeeps started with the same spring up front getting a different result. :thinking::crazyeyes:
I did this from a '13 JKUR to my '13 JKUS and with the help of some spacers front and back, I have a level ride. I was able to get all 4 springs and 4 shocks off of the JKUR shipped to me for $150 and did the work myself. It was easy enough to do, even for someone that has never changed springs before. There are plenty of videos on YouTube on how to do it if you're as unfamiliar as I was. I figured for the small investment of money and time it was worth a try. I noticed a slightly stiffer, but not overly harsh ride after the swap. Maybe it's the spacers, but I don't know???
Sorry I couldn't be more specific. Maybe someone else with way more experience can offer a better answer. :thumb: