27 to 29 spline swap 8.25

Before I get flamed, I've searched and not found my answer. I have a 27 spline 8.25 and want to swap it to 29 spline. Here is my question. Everyone says that inorder to do this swap you must swap the carriers, why, what is different about the carriers? Why can't I just throw in a 29 spline lunch box locker and 29 spline axles? What are the differences in the carriers?

Your axle shafts slide into your carrier. How do you plan on putting 29spline shafts in a 27spline carrier?

Axle shafts are not splines to a carrier. They slide in but the only thing they are splined to are the spiders. If they were splined to the carrier it would be a spool. are the shafts larger in diameter will they physically not fit into the carrier?

http://www.jeepforum.com/forum/f11/27-29-spline-8-25-swap-1403753/#post14000721

Why not just wait for the answer there?

http://naxja.org/forum/showthread.php?t=30441

http://naxja.org/forum/showthread.php?t=955202