I have a very similar setup as you with almost the same weights. I weighed mine with the wife and kid and all my quads in it, fully loaded except water as we rarely travel with full water.
I added air bags to mine and have a tune with exhaust brake. I have taken it over the biggest mountain passes in the Northwest and Montana without any problems. The exhaust brake is nice, I have to push the gas pedal to keep speed as it slows the setup so much.
As has been stated, you know you are over GVWR as I am. Although I would rather have a 1 ton and it would tow much better, I am fine with my current setup.