GMC Sierra 4500/5500/6500 trucks deliver proven power and performance. Pacbrake builds them even more powerful for towing and hauling. Command your ride with Wireless Air Suspension Controls. Install bigger tires on your Chevy with Pacbrake anodized, all aluminum Leveling / Lift Kits. Or let 'em know you're there with Pacbrake Air Horns. GMC Sierra 4500/5500/6500 kits by Pacbrake: Leaders of the Pack.