Engine Date Markings

I am rebuilding my 289 at the moment and picked up the block and crank from being acid dipped last week. On the block, right on the mating face to the sump, there seems to be a date stamp. Hopefully you will be able to see it in the attached photo, but if not it reads 6C31B. This would be a couple of days after the cast date of 6C29, so I guess it is the engine build date, but please correct me if this assumption is wrong. Is it normal to find a date stamp here?

Also, the crank has a stamp on it; WEC 1342. Again, is this a stamp that is normally found?

Here is another

Build date this is from a one family owned car a late MK1A and is similar to Duke MK1A old car said to be original, a motor out of another 1A B382001345 and I had a similar number on a very close car. So that is 5, I can count by my looking in the 5K14_ engine group pictured has a different employee last initial, I have seen 4 that were marked 5K14M

Engine data Marking

See attached article by Ron Fraser in Rootes review ( TEAE)

Gilles

Thanks Gilles. I will check that area for any code when I next see the block, however the code/stamp I am referring to is on the bottom lip of the block where the sump mating face bolts up to. I just wondered if it is normal to see a stamp here as I haven't read about one in this position before.

Didn't see

On my survey of 3 oil pans R and R'd I didn't see but that's not because they were not there. Next time I get one off I will look and I will try to be like a pal who has a set of reading glasses at every "station" in the garage because I missed seeing any stamping that our OP is referring to. A lot of times guy myself included will post this information with the hope another will find the straight story. When I read a selling Tiger owners insisting he had a numbers matching bell housing I had to laugh, numbers matching with a 5 bolt bell housing on tons of Fords.