Outer Limits 4x4 Board

My brother has a nh paj with a factory air locker and he has managed to snap one axle and twist another. After going to the wreckers and getting another two axles we have discovered that for some reason there is a difference in paj axles. Im guessing the factory locked diffs had different axles than standard? Is this the case, the blokes at the wreckers couldnt help answer this, so I thought ill come here, one of you should be able to shed some light on the topic for us.

Yes, the ones w/ the 3.5s run the air locker and 9.5in ring gear vs. the 3.0s run a 9.0in ring gear. I dont know about the diesels axles tho.

I fitted the factory locker to my NH and the axles are thicker and lenghts varied.
Steve