The American Thunder® header-back exhaust system is a true dual large 3.00 in. muscle car system for the person who is looking for a deep aggressive sound for their high horsepower vehicle. This stainless steel system is mandrel-bent for maximum performance, includes an H-pipe crossover to balance out the exhaust pressures, add hp and torque, and to help eliminate back-rap on deceleration. The specially selected Super 40® Series performance mufflers feature a large case to handle the added horsepower and provide a deep muscular tone flowing through the large 3.00 in. tailpipes. The American Thunder systems generally deliver an aggressive interior and exterior tone and are suited to the enthusiast who wants their performance to be heard. The sound level will depend greatly on the engine and level of modifications. Like all Flowmaster systems, the benefits include improved throttle response, power and mileage. Designed for an easy fit, these systems include all necessary parts and hardware for easy installation. Covered by our Lifetime Limited Warranty.