Standard-Duty Uncoated Full-Length Headers1964-77 Chevelle, Malibu, El Camino, Monte Carlo, Passenger Car 283-400Tube Size: 1-5/8"Collector Size: 3" 1964-77 CHEVELLE, MALIBU, EL CAMINO 283-4001970-77 MONTE CARLO 283-4001971-81 BELAIR, BISCAYNE, BROOKWOOD, CAPRICE, IMPALA, LAGUNA, TOWNSMAN 283-400Without smog injection or injection heads.Will fit with angle plug heads (Chevy aluminum only).Must modify rotary A/C bracket.Will not fit (Saginaw) close ratio P/S with 825 power steering box, 1967-69.Includes parts necessary to retain emission devices. (50 State)Modification to stock exhaust required to retain catalytic converter.For vehicles 1964 through 1974 without A.I.R. systems, considered as O.E.M. replacement parts when existing emission.