Like I said, based on my swag weight numbers for people, tools, etc., I'll be + or - a 100 lbs within the trucks stated cargo limit only if the hitch weight of 1700 is reasonable. Like you say, its probably closer to 2000 based on the weight of the trailer. I don't know if I have a "fudge factor" on the 2400 cargo limit the trucks door is telling me.
I wish these truck manufactures would say something simple like, "hey, you can put a max of x,xxx pounds of fifth wheel hitch in the bed of this truck as its equipped including a full tank of gas. For every pound you add or plan to add, to the cab, the bed, or any part of the truck, subtract it from this number.