Well, that is about all that Ford recommends for your truck. Anything over that figure usually results in extra wear on drive train and suspension components.
Many folks will add air bags or adjustable shocks or sway bars but all that does is make the load stabler. It does not change the numbers.
I am over weight with my Lance 1130. And I have a F350 dually with sway bars, Timbren overloads, Rancho shocks. Those things just make the load easier to carry. It does not change the fact that I am over weight.
So what next? Consider a pop up trailer or a smaller popup truck camper.
Chet
p.s. Welcome to the site!