Welcome to the RV Forum, dewsx2.
You can view the 2002 Trailer Life Tow Ratings here:
http://www.trailerlife.com/output.cfm?id=42175
Basically you are looking at two numbers: (1) The trailer GVWR`vs the rated tow capacity of the truck, and (2) the payload capacity of the truck vs the trailer pin (hitch) weight. Your truck has to be able to carry the actual pin weight and pull the actual gross trailer weight. Since you probably don't know tha actual loaded trailer weight when shopping, we use the trailer max loaded weight (GVWR) for estimating purposes.
The rule of thumb for trailer weight is to discount the truck's rated tow capacity by 10% and shop for a trailer whose GVWR is no more than that. If towing in the Rocky Mountains with a gas engine truck discount the tow capacity by 20%. The reason for the discount is to allow for additional weight carried in the truck (passengers and gear) and to give a bit of safety margin.
The 5W trailer pin weight will be about 20-22% of the actual loaded weight of the trailer. Once you fnd the truck's payload capacity, make sure the weight of passengers and gear + the trailer pin weight does not exceed that. This is typically the more restrictive number in half ton and 3/4 ton trucks.
