I just picked up my parts, it's not going to work, the offset is different between the 30 and 44 resulting in about a 1" difference in length of the axle shafts. Now I'm stuck with some brand new Rubi shafts, I would just get some custom chromo inners made but the ujoints are not 760's anymore.

 

The normal dana 44 and all the TJ u-joints are a spicer 760, the JK dana 30 is still a 760 but the Rubi 44 is something new, it has a 760 cap but the caps are about 1/4 further apart. It ooks like you can use the stock dana 30 outers and get some custom length inners made. I found some ford truck applications that are about 3/16" too long, but you can probably cut them off and they will be fine. You can also just get some custom alloy inners made to the correct length.

The Dana 30 lengths are 34.56" and 18.75"
The Dana 44 lengths are 33.56" and 19.75"

 

I knew that and don't even know why I was saying it. I'm thinking similiar to
S35 for the rear. I'm the one that is confused.

 

Here's a pic to compare

 

Hmm...I posed the question several months ago about what u-joints the X had, and no one really knew. The castings don't look like current 760's, but more like the old 297x which isn't supposed to be in production any more. That sucks that the Rubicon shafts are shorter, but I guess this is due to a wider/larger differential carrier.

 

The shafts are the same total length, just one is shorter and one is longer, the center of the diff is 1/2" different offset because of the pinion offset difference between the 30 and 44.