Odd slant 6 engine number

The engine number stamped on the machined boss is only six numbers. 223052. The boss is clean and undamaged. No other marks are visible. I figure it was a factory screw up. Block casting is2463430-7. Engine is in a 64 Valiant 200 conv. Has anyone seen screwed up engine numbers on other blocks? Thanks
Frank

Had a friend with younger and better eyes than mine check the number and he said that there is a Maltese cross after the last 2 in the engine number. .????

From the casting # on the block is this a 66 - 67 block?