Welcome to Grand Rock Company, where dedication, quality, efficiency and service are reflected in our everyday actions and commitment to our customers. For over 40 years Grand Rock has provided you with the broadest range, hottest technologies, and highest quality exhaust systems in the market. We manufacture and distribute over 3000 exhaust products, keeping your fleet up and running and maximizing your performance. Whether you are in need of a replacement exhaust system for your Heavy Duty Truck, School Bus, Medium Duty Truck or Pickup we have it! Dedication. Quality. Efficiency. Service.