i believe all of the denali and escalade AXNs are 3.42s. there are allegedly some unicorn AXNs in avalanche/esky ext trucks that are 3.73/4.10s maybe ?
swap is direct, did mine in a couple hours at friends shop.
gear swap on them arent too bad. it was a little intimidating diy, but the process kind of ensures you get X set right before you move onto Y, before moving onto Z. if you cant get it within spec at any step you dont move on.
setting the pinion depth is no.1 - in my case the shims that came with the install kit i got put me too far or too close. so i used the smaller, but setting the backlash in spec resulted in poor tooth pattern. tried the larger, still couldnt get decent pattern when backlash was set to spec. ordered more shims, they took for fookin ever - i never checked the existing shim because i never took the bearing off the pinion gear but i ended up cutting the bearing off the old pinion to see what shim it had, and it was money. the 9.5(14 bolts in general) also has an adjuster on one side youre not messing with shims on each side of the caps, just one side.
now to preface all this - the few guys i talked to that knew gears told me : the first set up you should always,ALWAYS, set it up with whatever shims came out of it. because that is what it needs 9 times out of 10.
i didnt really document much cause i didnt really know what i was doing, wasnt sure if it would make it more than 5 miles, didnt want to put out bad info. i swapped 4.10s and a trutrac into mine....so far so good though!