Kooks Universal 3 Inch ULTRA-GREEN Catalyst 3in Inlet/3in Outlet/4in Long/4.5in OD Body/7In OALKooks 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