ALL BBK Shorty Tuned Length Mustang 4.6 GT 3V Exhaust headers are manufactured with 1 5/8" CNC mandrel bent tubing for unrestrictive airflow and 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 4.6L GT 3V 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 Ford Mustang 4.6 GT are available with our optional high-temp show quality Silver polished ceramic coating or chrome finish. Direct bolt on – all new gaskets and exhaust hardware included with every kit.