my previous Dodge was a WC 57 Command Car, I rebuilt the trensfer case in that and noticed a slight difference but really it was an exercise in pure futility. I did buy some acoutic barier tiles and glued these to the floor under the front bench seat, that went a log way to quietening things to a more acceptable level.
When I 1st drovw the carryall the transfer case was noisy so I went out and acquired a 2nd hand unit which I stripped and rebiult. The gears looked fine, no pitting, to loss of hardening. New timken bearings. Still noisy so I rebuilt the original T/case with all new gears. No difference, even with the highest quality gear oil my money can buy. The moral of the story is buy good noise cancelling ear muffs

The most annoying thing here is a friend imported a fully restored WC 57 from the UK, a couple of years ago, the transfer case was almost silent!!!!!!
Cheers
Ian