C8OF-9600-C Unique 1969 air cleaner base with a rectangular vacuum actuated valve on the drivers side. Applications include 1969 Q code 428CJ (non ram-air), 1969 S code 390-4V, and 1969 Boss 302 Eliminator. About 16-3/8" inches in diameter. Early 1969 production through 2/17/1969, after that date there was a vent added for automatic choke issues. Ford part number C8OZ-9600-C.