Your limiting factor is likely the available payload of your truck with what you're carrying in it and what is available to carry via tongue or pin weight. To hit that 10,000 pounds of advertised towing capacity, you can only have a 150 pound driver and pretty much nothing else in the truck. Each thing you add deducts how much you can tow.
I wrote a blog page about this exact topic:
What Can I Tow?
It helps explain hot to figure out what you can tow and stay within your truck's ratings.