The 50 Series Big Block Muffler is our largest and quietest muffler made for tow vehicles, full-size trucks, large SUV’s and RV’s / Motorhomes. This muffler is made for more than just big cubic inch engine applications and has a very large Resonance Tuning Chamber to almost completely reduce interior resonance in large cab vehicles and enough case volume to handle engines under heavy loads. Significant improvements in mileage, torque, and horsepower are to be expected from this muffler, as well as decreased engine heat and wear. Available in 16-gauge aluminized steel and fully MIG-welded for maximum durability. 5 Thick x 12" Wide x 22" Long with inlet/outlet sizes of 3" and 3.5". Click on image for sizes and full part number listing.