Yes the '85 Federal is the '84 CA and other previous. My car is odd as uses '84 MY parts but has MY of '85 built in October, 1984.
huh.
Jeremy something or the other on here converted a true CA '85 to a Fed, he took pics and such if you are curious.
Either way it is not needed, remove it/plug it if you have to deal with visual inspections on Diesel. Or simply convert the car to earlier Federal bits and off you go.