I hope this helps you out. Saw this while viewing the manual prior to towing for the first time. This is where you should concentrate your efforts. Take your measurements, as shown on page 285, to determine if you need a WD hitch (it looks like you do). Starting on page 279, read ALL towing info regarding trailer weights, loading, hitches, and weight measuring.
284 Driving and Operating
Towing Equipment
Hitches
Always use the correct hitch equipment for your vehicle. Crosswinds, large trucks going by, and rough roads can affect the trailer and the hitch. Proper hitch equipment for your vehicle helps maintain control of the vehicle-trailer combination. Many trailers can be towed using a weight-carrying hitch which has a coupler latched to the hitch ball, or a tow eye latched to a pintle hook. Other trailers may require a weight-distributing hitch that uses spring bars to distribute the trailer tongue weight between your vehicle and trailer axles. See “Maximum Trailer Tongue Weight” under Trailer Towing (279) for weight limits with various hitch types.
Avoid sharp turns when using a step-bumper hitch to prevent damage. Make wider turns to prevent contact between your trailer
and your bumper.
Consider using mechanical sway controls with any trailer. Ask a trailering professional about sway controls or refer to the trailer
manufacturer's recommendations and instructions.
Weight-Distributing Hitch and Adjustment
A weight-distributing hitch may be useful with some trailers. Use the following guidelines to determine if a weight-distributing hitch should be used (shown on page 285).
NOTE: Helper springs and air bags will not increase loading capacity ratings. You are still limited to the original factory ratings by law, and you should never exceed any of the listed weights on the door sticker. You may want to check with your state's DMV to confirm.
If you are a racer, think of a WD hitch setup as being similar to subframe connectors on a race car, only they flex slightly, instead of being rigid. They make your tow vehicle and trailer act almost as if they were on the same chassis, with weight evenly distributed across all axles. Many brands are out there, but the added benefit of an Equal-i-zer brand hitch, is that it is also a sway control device. The towing experience is fantastic! No sway, despite tractor trailers blowing past you. It is the top-rated WD hitch in the RV industry. I bought mine from AdventureRV.net for around $425. Best I ever used on my car trailer or travel trailers. Closely follow the instruction manual, weigh your loaded truck and trailer as shown in your truck manual, properly distribute the trailer's weight, and you'll find that your truck will tow just fine without changing shocks or springs. Just be sure to stay within all limits.