This American Thunder® Crossmember-Back exhaust system is custom designed for most 1964-1972 GM A-body cars and is for the person looking for a complete 2.50-inch dual exhaust system with a moderately aggressive exterior tone and a moderate interior sound. With easy fit in mind, these aluminized steel systems feature all mandrel-bent tubing, an H-pipe to equalize the exhaust pressures for maximum performance and deep sound and includes a pair of specially selected Super 40™ mufflers. The mandrel-bent 2.50-inch tailpipes tuck up out of the way for maximum clearance and offer you two choices of tailpipe exit styles. Like all Flowmaster® systems, benefits include improved throttle response, power, and mileage. Designed for an easy fit, these systems include all necessary parts and hardware for an easy installation and is covered by our 3-year Limited Warranty.