An Original Equipment Size Oval muffler.The All-Welded Stainless Steel muffler is designed with 3 1/2 inch flow tubes to minimize backpressure and improve performance . The 3 1/2 inch end connectors are designed to mate with the OE pipe. The inlet /outlet tubes were designed without slots to provide for easy welding. If clamping of the system is desired, slot the ends of the tubes to help provide a good, leak free connection.