i made my comment from my personal experience, the link above makes me think the xxx, yyy... ect is nothing more than a cast code of some sort, not ment for use outside the factory. to identify the production year of your block just look on on of the bellhousing wings as i mentioned also.
They were cast intentionally by Ford as a way to amuse themselves while they read about people that try to figure out what the meaningless letters mean. It's kinda like an old Eagles album. Back in the day the guys at the record plant used to write little meaningless messages into the center of Eagles albums.
They were cast intentionally by Ford as a way to amuse themselves while they read about people that try to figure out what the meaningless letters mean. It's kinda like an old Eagles album. Back in the day the guys at the record plant used to write little meaningless messages into the center of Eagles albums.