For Checker. for C10 5.7L 1975-1986 & 5.0L 1977-1986 & Pickup 5.0L 1968-1973 & Pickup 5.7L 1970-1974 & Suburban 5.7L 1969-1986 & Suburban 5.0L 1977-1979. for C20 5.7L 1975-1979 & 5.0L 1977-1978 & Pickup 5.7L 1969-1974 & Pickup 5.0L 1972-1973 & Suburban 5.7L 1969-1979 & Suburban 5.0L 1977-1979.