Check out this website on Toyota.com:
http://www.toyota.com/upfitters/pdfs...rms3_20_07.pdf
It says that your camper and everything in it and should not exceed the Cargo Weight Rating (CWR) which is:
Maximum weight of cargo that can be installed on the bed including:
•Cargo (i.e. camper), equipment, etc. placed in the bed.
•= GVWR – curb weight – installed optional equipment weight - weight of passengers
•Never exceed rear GAWR.
This means that hauling any camper much over 600 pounds would exceed the recommended GVWR.
Questions you might ask camper sales people before you buy:
If you are in an accident and have exceeded these manufacturer recommendations - will your insurance company still cover you?
Would the police cite you for exceeding the recommended GVWR if you were in an accident?
Would Toyota honor your warranty if you have damged the truck and exceeded the GVWR?