If you'd like to reduce the noise from the glasspack mufflers on your Shelby Cobra side pipes, Flowmaster Slimeline side pipe style mufflers are a solution to sound pollution. They feature a 3 1/2 in. center inlet/outlet, and a 4 1/2 in. round body in various lengths. The cool 304 stainless steel case features a shell which prevents the outside case from generating extreme heat. These Flowmaster Slimline mufflers are made in the USA, and available in varying degrees of exhaust notes, including mild to moderate. Now you can cruise in your Mustang without disturbing the peace.