You shouldn't have any trouble pulling your toy hauler. The empty weight of the trailer should be around 11 to 11.5K. Once you have it loaded take it to a scale and weigh the rig. These trailers tend to be heavy on the kingpin when they are empty because of the large open area in the back. Don't make any adjustments to your suspension based on empty conditions. If the loaded condition makes the rear end feel soft you may want to add airbags. Is your truck a long bed? If it's not you may want to consider a sliding 5th wheel. This will let you set the trailer back a little in a tight spot so the nose of trailer doesn't hit the back glass of your truck. On the road you can bring the kinpin forward to put the weight right over your rear axle.