Some really quick Math puts you at 6200 libs... before you've put any fluids in the car...
You'll be okay with this load: as long as the 8000 lb towing capacity number is correct.
But you've already seen the overheated RVs around you. I'd try to lighten up your package, and not put so much of a load on your rig.
Keep in mind that I'm a "Fraidy-Cat"; who never likes to push the limit...