Lol its gonna tow like crap with 6k behind you and 24's lol... I hauled 6500 lbs in a dump trailer behind mine. It had enough power for city driving. But highway kinda sucked. But I'm on 18s...
Also height and wind resistance come into play on the highway.
Make sure to upgrade your brakes as well as making sure the trailer brakes are in good shape.
I have a CAI, BB tune, E fans, borla muffler and 3.73 gears.
Check to see what gears you have as well.
I have also hauled a 20 ft enclosed trailer that was about 4ft taller than my yukon. Used it to move and it really sucked on the highway. If it wasn't so tall it wouldn't have been nearly as bad.
I pull our 4k boat just fine though. Also a pontoon in the 4k range but it's taller. Same thing tows it fine