Topic: Engine date code

[twister428]

Does anybody know the origin of the 2 dots under an engine date code and what they mean?

[J_Speegle]

I'm guessing your referring to the casting date rather than the assembly date. Believe it didn't "mean" anything other than it was a running change/pattern incorporated at the casting plants after a particular time as we see it on third member housings also. Think it was first seen/used in 69 - may have just helped in the orientation for reading the numbers right side up but its usage does not seem consistent (have it on some 69 castings and others without)

Example have a May 69 date with the dots and a October 69 without


Third member example with dots





And a FE block





351 (Dec 1970 Without dots

[twister428]

Thanks for the input. What you say varifies what I always thought.

[J_Speegle]

Received a PM that referenced a comment from a generic Muscle car book suggesting that the dots and no dots related to different shifts. Not clear what car manufacturer they were referring to (writers included a Galaxies and a Pontiac restorer) and the text referred to singel and double dots. Never heard of single dots on a Ford cast part so maybe the reference was related to non- Ford built cars.

At this point a single unconfirmed reference - the search for complete understanding continues

[jwc66k]

There is a possibility that the dots indicate a "9" as opposed to a "6". Remember, the guy putting them in the mold was looking at the mirror image.
Jim

[J_Speegle]

There is a possibility that the dots indicate a "9" as opposed to a "6". Remember, the guy putting them in the mold was looking at the mirror image.
Jim

That was a thought until you find the double dots under the 0 (for example) representing a 1970 cast part