To be absolutely certain, you should:
* Check the sticker: Look for the GVWR on the sticker located inside the driver's side doorjamb. This is the most reliable source.
* Consult the owner's manual: If you have the original owner's manual, it will list the GVWR for your specific truck.
* Check the truck's title: In some jurisdictions, the GVWR might be listed on the title.
Keep in mind that the GVWR is the *maximum* weight the vehicle is designed to carry, including the truck itself, passengers, cargo, and any added equipment. Exceeding this weight is dangerous and illegal.