I am trying to help a friend be more informed on what size and weight trailer he can tow with his 2012 crew cab Silverado 1500. He sent me a pic of the door sticker. It has a gvwr of 7000lb and gawr of 3950. Cargo capacity is not listed like on my Ford.
Cargo capactiy should be on the door sticker like the above photo. As fas as towing capacity, the detail is in the owners manual. Go the section on towing, it lists the different models with engine choices and gear sets, then lists max trailer weight and GCVW. To determine gear set, look for a tag in the glove box with the RPO codes. It'll be one of 3 codes, GU6 is 3.42s. GT4 is 3.73s. GT5 is 4.10s.