Hi Kid,
Are you sure the 0 is not a G? There should be a G # (1 or 2) depending on what shift the unit was made.
The Dec 27th '66 date would seem too far in the past for your car, IMO, but who knows if it sat on a rack somewhere for a long time before being used. The 2 Camaros I have with original rears has one 'BJ' rear (LOS plant) dated 0404 for a 4B (April 13th per UOIT) dated trim tag and the other 'QK' (NOR plant) dated 0331 for a 5B dated trim tag.
Regards,
Mike