Ford superduty inventory ?

Hedgehog, I have real world experience with an F350 6.2 gasser with 4.30 gears. We left Wisconsin the middle of May pulling a 36 foot 5er toy hauler, I weighed in at 14, 200 pounds. I am currently in Anchorage, Ak 5500 miles from home, we pulled up some 8 to 9% grade mountains (Rockies and the Top of the World Hwy). There were times I was in 2nd gear at 3500 rpm wondering if I was going to start rolling backwards down the mountain, that was when I wanted the disel torque. But, when the diesel guys went for their oil and service jobs and paid $400 plus and I paid less than $100 I was convinced I ordered the right engine.
BTW, I am averaging 8.1 mpg pulling the rig.
IMO, if you will be towing on mostly level ground the gasser will be fine, if planning on mountain driving, get the torquey diesel.