1-7/8" Header and GREEN (H) Connection Kit. 2007-2010 Shelby GT500 5.4L 4V 1999 Pontiac Firebird The rebound valving has a

The rebound valving has a progressive curve that is strictly determined via orifice control

as often the first 10+ clicks provide no changes to the valving

1 EA J427GP-350 Front Coilover Kit

5" DOM Mild Steel Tubing for added strength

You can take it off and your lap times will not change

1-7/8" Header and GREEN (H) Connection Kit. 2007-2010 Shelby GT500 5.4L 4V 1999 Pontiac Firebird The rebound valving has aKooks Headers and Exhaust has been the leader in the High Performance Exhaust Industry for over 50 Years! Since 1962, Kooks takes pride in offering the best Headers and complete exhaust systems for your street, race and off road applications. We have won hundreds of championships and set countless records in the NHRA, IHRA, NMCA, NMRA, NASCAR, NASA, SCCA and many other racing organizations. Now with three generations of family leadership, we are proud