Interesting reply I got from a friend when asking about a rear for the MJ...
"8.25 29 spline with KJ disc brakes. Easily available with 4.10s. An early Liberty axle is perfect size, just more brackets to remove, but will already have the disc brakes.
Cheap and plenty strong. No c-clips, perfect width. No carrier break when regearing. Small housing offers good clearance. No draw backs compared to an XJ/MJ 44, except they need a good cover - but they all need a good cover anyway...."
Seen anything at the yard?