JBA has been building and testing headers for the 5.7L HEMI since it was introduced in 2003. With this experience our engineers were familiar with the design and flow characteristic of the heads and knew what the engine would respond best to. 
The engineering team at JBA addressed the critical short comings of the 5.7L HEMI exhaust manifolds with a fresh design that started with high flowing 1-3/4" mandrel bent stainless steel tubing. By giving each cylinder a smooth unrestricted path, back pressure is reduced and flow goes way up. The giant 3" collector was engineered using JBA's patented Firecone® - a unique directional device similiar to what you find on a long tube race header - which improves flow by providing efficient scavenging of exhaust gasses. 
Other standard features like thick 3/8" CNC laser-cut flanges, O.E. style JBA sealing dome connection to the exhaust and high quality hardware make them a highly effective upgrade for the HEMI. Bolt-on a set and feel the JBA difference. 3/8" thick laser-cut single piece flanges 
 1-3/4" 409 stainless steel primaries 
 Patented JBA Firecone® merge collector 
 JBA sealing dome connection with exhaust 
 Premium quality hardware and gaskets  Direct bolt-on installation 
 Will not void factory warranty 
 Optional ceramic coating (thermal barrier) 
 50 state smog legal Increase hp & torque throughout RPM range 
 Improved throttle response 
 Reduced back pressure 
 Reduced under hood temperature 
 Increased passing power 
 Increased low-end torque 
 Makes engine more sensitive to other modifications (intake, chip, supercharger, etc.) 
 Improved engine compartment appearance 
Allow 1 to 2 weeks for delviery