BBK 11-20 Dodge Challenger Hemi 6.4L Shorty Tuned Length Exhaust Headers - 1-7/8in Titanium CeramicThese BBK Performance shorty tuned Length exhaust Headers are designed and constructed as direct fit replacements for all 11 23 6. 4L Challenger Charger Hemi applications. Each header is manufactured with 1 3 4 in. CNC mandrel bent tubing that offers unrestricted exhaust flow for increased horsepower and torque over factory OEM manifolds. BBK tuned Length headers offer improved scavenging waves for better combustion, which leads to improved