Chevrolet 2003 Silverado 1500 Pickup Owner's Manual page 363

The Gross Combination Weight Rating (GCWR) is the In Canada, write to:
total allowable weight of the completely loaded
vehicle and trailer including any passengers, cargo,
equipment and conversions. The GCWR for your vehicle 1908 Colonel Sam Drive
should not be exceeded. Oshawa, Ontario L1 H 8P7
You can ask your dealer for our trailering information or
advice, or you can write us at the address listed in
your Warranty and Owner Assistance Information
Booklet.
General Motors of Canada Limited
Customer Communications Centre, 163-005
4-82