I just recently purchased a Rock Trac t case that came out of a 2010 JK that had 30k miles on it. I'm looking at the very least replacing the 231. I have plans on doing the AW4 to AX-15 or Nv3550 swap. While swapping the tranny that's when I plan on going with the Rubi case. My first question is will the Rock Trac bolt up to the AX-15 as I know that the Rock Trac was only bolted up from the factory to the NV3550 and the NSG370? My next question is what do I do with my speedo? I was thinking of just running without it. It's more of a trail rig anyway. And the last question is: since I do have 2 other Np231's lying around, has anyone done or heard of someone doing a 231/241 doubler? I've tried to research a kit for the rubicon mating to the 231 and I've come up empty-handed. The only thing that pops up on the radar is the northwestfab kit for a 231 mated to their ecobox. It doesn't mention the rock Trac that I'm aware of. Any help would be much appreciated.