www.cobrajet.org,,,,,and read. It may have a number and it might not. Some blocks have it inside the water jacket. Good reading.
Not the sharpest knife in the box, but from what I know that "D1F44" would tell me that this is a 1971 part #. You might want to find someone else to either agree or disagree with this.....Rich
It would be helpful to tell us if these are stampings or raised castings and where you found them? Pretty sure the "DIF 44" is a casting plant ID and mold number. It will not help you ID the block. What is the date code located between the oil filter and the oil pan rail? It should be in this format "9F23"
Just above the oil filter adapter will br the buid date etc. Engine serial number should be on the back (firewall) of the left cylinder head on the flat area. Can be read with a mirror.