The "experts" and the weight police will give you all sorts of formulas - and probably try to convince you that you don't have enough truck. I already see a couple replies telling you to get a one ton dually.
Let me speak from experience ....
As you can see in my signature, we pull a slightly larger 5th wheel than the one you're thinking about, and we do it with w 3/4 ton MegaCab.
I expected to have to add overloads or airbags but didn't even have to do that. 30,000 plus miles of towing and NONE of the problems we've experienced had anything at all to do with pin weight or truck capacity.
We do have a heavy Superglide hitch which we may or may not need, but it's worth it to me because it is practically idiot-proof. I never have to worry whether I can turn sharp enough, I just go.
Of course, our two dogs probably weigh less than yours. :B
