Right so my truck has a 17100 lb GCWR. Even if my truck and trailer were both at max GVWR(7700 lbs and 5500 lbs) I am only at a GCW of 13200 lbs. Even at 7000-8000' I am below the recommended GCWR.
The frontal area should be right at the limit I would think. My trailer sits very low and the front is sloped pretty aggressively though..