What are these numbers?

[Tommy]

I was told it was a 350
I found these numbers on it
CFD207

 

[Philip]

On what part of the block was that photo taken?

 

[Tommy]

Rear of the engine on the passenger side towards the bottom we found them when removing the original transmission

 

[Philip]

Not sure what they are. The numbers to ID the block will be the date code and casting date along the upper bellhousing flange and the stamped number on the block in front of the passenger side head.