Read through the post on how to calculate GVWR and GVCWR. This was a hard lesson for me that you "load out" before you "tow out." I have a 9500 lb tow rating but my actual max is 6500 lbs because of the tongue weight (TW). I'm hauling a family of four so I could maybe squeeze a little more cargo if I didn't have 4 people but my hitch is 500 without a weight distribution hitch (WDH) and 950 with. WDH weighs 100 lbs leaving 850 for TW.
Look at the stamp on your hitch as see but I bet it's rated to 1,000 or less with a WDH. All the other numbers matter but this may be a limiting factor even if you can squeeze a little more room on cargo.
Good news is, that means you should have some margin in GVCWR which gives extra power for towing up hills.
