I just looked up Nissan lockers up on the ARB web site.

Per ARB The 02-05 model had 1.26" rear shafts with 31 splines. The 05-and up should have 1.31" shafts with 33 splines.
It looks like the front axles are all 1.20" with 29 splines.

Based on what ARB has listed (unless there is a gear,or bearing weakness etc) the Gen-2 models should have stronger rear axles and the fronts should be the same.