ALL BBK Shorty unequal Length Mustang 1999-04 3.8/3.9 Exhaust headers are manufactured with 1 5/8" CNC mandrel bent tubing for unrestrictive airflow and one piece laser cut 3/8" flange for added strength and durability. ALL BBK Headers are Pressure tested to ensure leak free performance. Each BBK Mustang shorty unequal length exhaust header for the 1999-2004 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 Ford Mustang V6 are available with our optional high-temp show quality Silver polished ceramic coating or chrome finish. Direct bolt on – all gaskets and hardware included.