Flowmaster 9430409 40 Series Race Muffler - 3.00 Center IN / 3.00 Center OUT - Aggressive Sound Durable fully welded 16 gauge aluminized steel - two chamber race muffler Good decibel reduction over open headers No internal packing to blow-out Race proven patented delta flow technology - designed for maximum horsepower and torque 4" by 10" muffler body