2003 GMC Sierra 1500 Pickup Owner's Manual - Page 343

Q: What if I want to add heavier equipment to my vehicle? A: You can add heavier equipment on the front of the vehicle if you compensate for it by carrying fewer passengers, less cargo, or by positioning cargo towards the rear. This has the effect of reducing the load on the front. However, the front GAWR, rear GAWR and the GVWR must never be exceeded. On some vehicles equipped with certain front mounted equipment, such as a snow plow, it may be possible to load the front axle to the front GAWR but not have enough weight on the rear axle to have proper braking performance. If your brakes can't work properly, you could have a crash. To help your brakes work properly when a snow plow is installed, always follow the snow plow manufacturer or installer's recommendation for rear ballast to ensure a proper front and rear weight distribution ratio, even though theactual front weight may be less than thefrontGAWR, is and the total vehicle weight less than the GVWR. Maintaining a proper front andrear weight distribution ratio is necessary to provide proper braking performance. 4-62