I run a old 95 3500 dually with the 96 6 speed case
2wd... works great pulling my 43' enclosed.... it
has a 4.10 gear with the tallest tire I can get...
still wish I had 1 more gear to keep the revs at 1900
My 2wd can get stuck pretty easy so the 4wd would help
that but the 4wd burns more fuel(more weight and drag)