Here is a thought. Maybe you can compare to this...I towed a 12,000# fifth wheel with a 2006 F350, 30 Valve V10 with 365 HP and 460# (iirc) torque. Rear gear was 4.10. And it did OK.
What your truck is a lot less power and gear. But so less, is the weight of your trailer. When comparing the two, probably pretty much the same result. So I guess your will do "OK" too.
This is why I suggest you give it a try. I actually was not that happy with mine when I stepped up to a 14K trailer. But it did tow that trailer for some 6000 miles. It worked hard at that task. Never complained. But it did struggle. I have a great respect for that engine, as a result. But I felt it was better off with a new owner that had less requirement for it.