Thanks for the info, Mike. My 1971 parts manual doesn't seem to include this valve at all, which seems strange if it was introduced during the 1970 model year. Do you know if there's a parts manual available that includes a description of this valve?

Scott Hollenbeck Administrator, Mustang 428 Cobra Jet Registry Owner, Muscle Car Research LLC 1970 Ford Mustang Mach 1 2006 Dodge Charger SRT8 1995 Chevrolet Impala SS