1975-1981 Camaro, 1975-1987 Chevelle, 1975-1979 Nova, 1975-1987 Monte Carlo, 1975-1991 Mid Length Size, 1978-1987 Olds Cutlass&442: 283-400, Primary Tube Size 1.5", Collector Size 2.5";Tuned-length primary tubes for better performance; Mandrel-bent tubing for smooth exhaust flow; Light weight & sturdy 16 gauge tubing; Mandrel-formed Power Plenum collector for low back pressure; Sturdy, leak-tested O-Ring port seals; Engineered for a precision fit; Designed for easy, trouble-free installation; Includes all mounting hardware and premium gaskets; Shorty style header, will also work on catalytic converter equipped vehicles. Head pipe fabrication required;