Acei looks like your are looking at BROCHURE payload numbers. They mean absolutely nothing when it comes to determining actual payload of a specific truck. The 4K numbers you see are for a gas truck without any options. Take a look at some of the payload capacity labels on the dealers lot.
An F350 Crew Cab long box XL diesel SRW, with NO OPTIONS, has a payload roughly 3700lbs. A gas has 4000lbs. Diesels weigh more. Based on your list of weights you will be 260lbs under GVWR with the diesel. I guess it depends on how close to GVWR you want to be. You will be under your 7000lb axle rating.
Your call. If I was full timing with those weights I'd go with the F350 dually for the little bit extra money. When your spending these kind of dollars, $1000 isn't that much and gives you a GVWR of 14,000lbs and a 9650lb rear axle rating. That's gives you over 2000lbs add'l payload.
I'm only talking Ford but it's pretty much the same discussion with the other manufactures.
S
