Help. I have a new 2500 HD LTZ that sits high, with probably a 6 in drop, and has the new 2.5 receiver. My old hitch head is solid and does not adjust up or down. So I want to start over. I want to tow a 27 ft Airstream with dry weight of 4545 lbs and with a listed 550 lb tongue weight. I want weight distribution and sway control. Suggestions?