ALL BBK Shorty Tuned Length Mustang 4.0 & 3.7L V6 Exhaust headers are manufactured with 1 5/8" CNC mandrel bent tubing for unrestrictive airflow and one pierce laser cut 3/8" flanges for added strength and durability. ALL BBK Headers are Pressure tested to ensure leak free performance. Each BBK Mustang shorty tuned length exhaust header for the 2005-2010 4.0L V6 and for the 2011-2014 3.7L V6 Ford Mustang has been designed and dyno tested at the BBK headquarters in Southern California to Maximize performance. BBK’s Mustang headers offer distinctive quality that guarantees many years of top performance. These BBK CNC Series headers for the 2005-2014 Ford Mustang V6 are available with our optional high-temp show quality Silver polished ceramic coating or chrome finish. Every Header will fit alll stock or aftermarket exhaust systems We recommend a BBK High Flow X pipe to add even more performance. All gaskets and hardware included.