Flowtech Headers are the perfect combination of quality and value. These shorty style headers fit the popular 2011-2014 Ford Mustang 5.0L V-8 models. CARB EO# D-115-28 Features: Mandrel-bent 409 Stainless Steel tubes provide consistent tubing diameters for smooth flow and increased exhaust velocity Heavy duty 16-gauge tubing for increased strength and durability Smooth transition, 1-7/8 diameter primary tubes are used for increased exhaust flow increasing performance and improving throttle response OE style 2-1/2 collector connects to factory exhaust head pipe without cutting or welding TIG-welded, machined 3/8 header flange for a leak-free seal and maximum strength Premium aluminum header gaskets included Available finishes include Natural (PN 12140FLT), Polished (PN 12141FLT), and Silver Ceramic Coated (PN 32141FLT) finishes These headers are a must upgrade if you are using a cold air intake, cat-back exhaust system or tuner