You need to list the trucks weight numbers GVWR, RAWR, maximum tire load. AFW will have around 20% pin weight. If you loaded that FW to 15,000 lbs, you'd have a pin around 3,000 lbs, plus another 200 lbs for a hitch. I am thinking you'd be at, or just over your RAWR, close to max tire, and obviously over your GVWR.
If you towed at the UVW of the FW, it may fit, but you can see where this is going.
Jerry