6500 lb with 2001 Expedtion- 4x4 5.4, Adequate?

We have a 2005 Expedition 8900# tow capacity and 14,500# GCWR and tow a 28' 4800 lb. dry. I've checked the weights on our way out 1/2 doz. times and found trlr. axles at 5400,rated at 7000. but it puts my TV axles near max.at 4,200 and 2900#. I have plenty of room for more weight in the trailer but can't take advantage of it without putting my axles and/or TV gvwr over. I have the 5.4 and 3.73 rear with Reese Dual Cam and E rated tires, it pulls like a dream even in the mountains.