The numbers will nearly always be different than the published weights or the door sticker. It depends on who and what you have in the truck at the time you weigh it. Best practice is to fill up the fuel tank(s) and load everything and everyone in the truck that you would have when you are ready to hitch up and head out (including the fifth wheel hitch if that's what you'll be towing). Make sure to get on the scales so that you'll get separate front and rear axle weights, too - the rear axle reserve capacity is the most common limiting factor when calculating remaining payload for tongue/pin weight.
Rob