Well welcome to AZ!

I towed a large UHaul trailer completly full from phx to flag up 5kft. Its only a 2 hour drive but the truck did it flawlessly with a pretty much stock engine. Tow alum boats and sometimes 2 3person seadoos just fine.

I'd be most worred about the tranny. Its not rated for towing. I'd swap the fluid out with some redline mt90 beforing leaving for some better protection. I really think that it will be too much weight with all the stuff in the back. A helper spring or a AAL would be your best bet. Might want to upgrade your bumper also.

Josh