I have done it both ways,
The T-Case in N and the Tranny in 2nd on the way out to Elko, NV (1698 miles)
AND
Dropped the rear shaft on the way back; Reasoning that 1st, I had an extra 1700 miles on the odometer that didn't need to be there, Also I was Flat Towing back in Snow Season Thru the Rocky Mountains, which is way HARRIER than pulling a trailer as flat towing has a DEFINNITE PUSH that will "Fold You Up" in down hill braking, and wants to push you to the "Outside" of a turn (You Have NO TOWED VEHICLE Braking),
AND
Without the T-Case turning, its Free Wheeling, Less Drag (Part of the above)
AND
It's only 8 bolts which are so easily accessible ....So Why Not?
CAPT