The 50 Series Big Block muffler is made for more than just big cubic inch engine applications. Its large case size with internal tuning chamber provides mileage and power gains along with maximum sound control for a quiet interior tone, even under heavy loads. Well suited to heavy duty vehicles such as full size trucks, SUV's, RVs, and tow vehicles. Constructed of 16 gauge aluminized steel and fully MIG welded for maximum durability.