C9AZ-6A664-A Original used hose that connects the valve cover oil cap mounted PCV valve and the front of the Quadrajet carburetor base plate on 1970 through 1971 Mercury and Ford 429 Cobra Jet engines only. Used hoses will have faded striping (if present), and clamp impressions. Very often the rubber will be hard and showing some degree of stress cracks.
*Note - These molded and contoured hoses were designed to work with original style PCV valve (modern 90° PCV valves won't work). Additionally anything other than period original intake manifolds, valve covers, and Rochester Quadrajet carburetors can also alter the position and distance in the relationship of the PCV valve and carburetor spacer plate.