See also:

Accessories and Modifications
When you add non-GM accessories to your vehicle they can affect your vehicle’s performance and safety, including such things as, airbags, braking, stability, ride and handling, emissions systems, ...

Replacing Restraint System Parts After a Crash
WARNING: A crash can damage the restraint systems in your vehicle. A damaged restraint system may not properly protect the person using it, resulting in serious injury or even death in a crash. ...

Total Weight on the Vehicle’s Tires
Be sure the vehicle’s tires are inflated to the upper limit for cold tires. These numbers can be found on the Certification/Tire label. See Loading the Vehicle. Make sure not to go over the GVW ...