So I have had this JK Dana 44 rubicon axle sitting in my basement for a while now just collecting dust and I was down there a few weeks ago and I had a revelation. I was staring at it, drinking some beers and decided to tear it apart and see if the hub, rotors, bracket and caliper out of my KK would swap over. Guess what? All of it does with one very small mod, and this mod isn't really necessary in my opinion, but you can be the judge of that. I really believe it wouldn't jeopardize anything, but like I said its your call on that. Everything bolts right up. Now based on everything that has been said over on the SFA section, its known that JK axles will work. I do not think anybody has swapped over a JK axle into a KK or KJ, that I know of, and supposedly just any JK axle is plug and play, and I believe it is because the computers are all the same between KK's and JK's. In my case I took out the JK hub which is 5x5, however mine is 5x5.5 because its actually a JK J-8 MIL SPEC axle, but basically the same as any JK axle, D30 or 44 except for the major difference of having a .31" tube wall compared to the .25" on all JK axles you will be able to find. Its a JK axle nonetheless. Anyways I took out the hub and the KK hub swaps over and bolts right up so you can keep the 5x4.5 bolt pattern and keep the computers happy. Which has always been the biggest hurdle. Everything else like I said ( rotors, calipers, and brackets bolt right up too, both JK and KK hubs are 32 spline also at the stub shaft ). CAN WE SAY SFA KK SWAP?????? using JK axles.
O! I forgot about the tiny little mod you can do to be legit. So the JK unit hub has a slightly larger outer diameter, the diameter of the hub that fits into the knuckle. Its a very very small gap almost to the point where its not necessary, however its easy to have a ring fabricated to compensate for this loss, and have it fit into the inner knuckle so the KK hub fits snug in there like the JK one does. Easy as that, and all the rest bolts in. From the few pictures you can see what I mean. I had my father fabricate a couple rings for me and I can give specs on those if you want. Anyways If anybody wants more info, fire away. I am gonna park the KK and start the SFA swap soon. Its a pretty easy swap in my opinion, and I attempted it a few years ago, however life got in the way (had a daughter, moved and worked a lot) so it got put on hold, and I'm glad it did because at that time I was gonna do it with a D30 out of an xj. I will post a few pictures, and if anybody is more interested I will be glad to share my thoughts and answer any question. I have a ton more pictures of what I have so far and I will be taking pictures of the swap as it progresses. I don't have a timeline, however I will be fabricating all of the arms myself and will be using a Clayton crossmember for the front long arms. 
my goal is to keep this wallet friendly as well and try and open up a train of thought that revolves around doing something like this on a budget or sort of budget. JK axles can be found on CL for $300-500, Clayton crossmember is $300, JK steering box $300, Johnny joints or Heims plus DOM tubing ~$1000, etc... etc.... I'm hoping under $3k for the whole build minus tires. I'm sure I'm missing stuff like coil overs and springs and shocks and what not, but I believe I can build it for around $3k minute tires. I have a set of 35 12.5 17 Trail Grapplers im gonna put on it. I know people on here are gonna flame me thinking a 3k budget is crazy, but I'm gonna fab everything myself and I believe it won't cost any more. BTW JBA is in the process of engineering a long travel system for the KK, and I must say what he's thinking is totally crazy and beyond awesome for the KK. It will take the KK to crazy awesome cool. But I have a feeling it will be pricey.
