Brent Posted-
KULTULZI have not been able to crack the date coding. Can you tell what date this head was manufactured?
#'s under valve cover:
63% of original size (was 800x190) - Click to enlarge
# under exhaust outlets:
63% of original size (was 800x190) - Click to enlarge
Data on face (There is an A5 under the X-out:
63% of original size (was 800x190) - Click to enlarge
Your DATE CODE is 5 1 D which would be 1955 - JAN - and D the day of month.
The X signifies a modification in the mold and D 4 confirms 4th day of month.
Now to have a NUMBERS CORRECT CAR/ENGINE ASSY, the CYL HEAD DATE CODES must be at the same or within a few days as once they come out of foundry, they are machined and then assembled, then assembled to a short. THE ENGINE ASSEMBLY is then shipped to whiscruber vehicle assembly plant it is on order for. Theory only as many things can happen within the process.
This is how you would document the engine for sale, by keeping a concise build sheet to go with the car.

Date Casting Code - 1st Character Indicates Year - 2nd Character(s) Month - 3rd Character Day
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