Jeff : The page I noted, page 15 from June 1968, was originally added by Change No. 27 in August of 1967. Something was revised on this page in December of 1968 by Change No. 29, and finally in June of 1968 by Change No. 33. The page 15 that you have probably shows either Change No. 32 or Change No. 29, depending on how Ford decided to reference Changes when none were made on a specific page. In either case, based on what you have noted, the addition of the C7ZZ-18C306-B occurred between April and June of 1968. Of course this doesn't mean that this part wasn't used by the Factory prior to that, just that it wasn't available as a Service Part until then.
Bob
