225 Engine Casting Number Identification

French demon said

I don't know if it helps, but here's the number of my 1971 slant six :
View attachment 1716006338
1 = 1971
B = Hamtramck
145923 = serial # of the car (the complete VIN is LL29B1B145923)

This number is located on the passenger side of the block, under the 6th spark plug (firewall side)

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Thank you very much. My CID is 4F 221369 but I think it's kinda strange. My VIN is VL41C4F221369, so the CID is the same as the VIN's last 8 digits, so nothing wrong with that.
The first letter of CID is the building year, so "4" is correct for 1974, but I can't find a plant coded with an "F". The letter "F" is also a code for the model year of 1970. And then there's the number on the driver's side, 2806830-7. Doesn't that mean that the block is a 1970's block?




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