what is this?

thanks for the diagrams......I put a new radiator in it but I still have the old one in the basement and is has no CCEGR valve on it and it is the original radiator .....My 73 dart 340 sport has a NOX valve on the firewall....But my 72 dart swinger slant six does not..... I don't know the slant six engine history if it is original to the car or not....maybe it was changed with a later style slant six.....I know on small blocks above the pan rail on the passenger side it has the VIN number....Do the slant sixes have the VIN stamped on them anywhere? If so, I can check to see if it matches