These are Trailer Life's tow ratings for 2010 vehicles; its a good staring point to determine what your truck can haul: http://www.trailerlife.com/Images/Di...wGuide2010.pdf
According to Jayco, here are the specs of the vehicle you are interested in:
* 298RES Specifications
Unloaded Vehicle Weight 7,300
Hitch Weight (lbs) 870
Gross Vehicle Weight (lbs) 9,200
Cargo Carrying Capacity (lbs) 1,900
Exterior Travel Length 33'11"
Exterior Height w/AC 133"
Interior Height 81"
Fresh Water Capacity (gals.) includes water heater 76
Gray Wastewater Capacity (gals.) 32.5
Toilet / Black Wastewater Capacity (gals.) 32.5
Sleeping Capacity 3-8
Remember, UVW means unloaded vehicle weight - empty of all the stuff (water, propane, food, clothing, supplies) you might take. Also, options you add can affect the weight. Probably, you should figure on the GVW (Gross Vehicle Weight) as that is the maximum your trailer could theoretically weigh. If you are near the top of the weight recommended for your truck, consider carefully. Generally, less tows better than more.