Re: Rear Axle... Size...Gearing...Material?
The 230mm is only in AL not Iron, 99% in this case it'd be more cost effective and easier to configure or find a jeep packaged with that axle, 4x4 humi, OR2? than swapping in the larger diff, in this case a little over a half inch larger gear set.
That 1/2" isn't as pivotal in ring gear diameter in independent diffs as when looking at solid axles. These diffs are not stressed in the same way, as well they are substantially designed for resistance to deformation or breakage even in comparison to the big boys.. The viper uses a different/IRS version of the d44al/hd with a ring gear about the same as the 215mm. The similar gearset in the WJ was subject to different forces.
I just beat a C7 like it was a criminal and it has an almost identical gear size through sport cups with 500rw. Dissimilarish forces yes but both cars ride on 28"ish tires that are almost a foot wide and made of bubblegum.
Meaning you might not need to be crazily concerned with the exception of a LSD, an obvious must. Even with the hemi on 33's you won't likely break the "dif" anywhere you could driive a Wk2, they won't be the weak point.
You got me curios though! You planning a hardcore build, luxoliner, expedition WK2. It would be awesome to see a street driven Wookie on 35's.