Truck Camper Magazine is pegging a fully loaded 1160 at 5,991 lbs and a 1165 at 5,795 lbs. They don't have the data on the HOST unit.
They sure are pretty, that is for sure. You just can't believe that all that space and comfort is on the back of a pick up truck, heated floors, dry baths, full wardrobes, island kitchens, theatre seating, basement storage......that is because is shouldn't be. It's just too **** big! I can see a single slide, but anything more and I say go get yourself a class C and keep another unsafe, aftermarket modified vehicle off the highway.
I have a 2013 EC 950 which is a SINGLE slide and I tip the scales right at my GCVWR of 14,000 lbs.
I can't see how any of these double and triple slides can safely be carried on anything less than a 5500 truck.
But as zb39 said, a gasser will definitely increase your payload.