Ford carburetor spacers are identified by basic part number 9A589. The spacers used on the 428 CJ and SCJ engine are made of a black plastic material that is similar to bakelite. The spacers are not marked with an engineering number.
|Applications||Service Part Number|
|1968 - 1969||C8AZ-9A589-G|
1968 and 1969 engines used a spacer that is 0.28" thick, stamped with the word "FRONT", and does not include a fitting for the PCV system.
1968 - 1969 C8AZ-9A589-G Spacer (images courtesy of Jim Woods)
The 1970 spacer includes a rear-facing fitting that's used to attach a hose that runs to the PCV valve mounted in the passenger-side rocker arm cover.
1970 D0OZ-9A589-A Spacer
Note that the bore sizes of the intake manifold (1.59" primary, 1.68" secondary), spacer (1.60" primary, 1.70" secondary), and carburetor (1.69" primary, 1.69" secondary) are not consistent.