I can not make out any numbers on the pan rail of my 73 340, there is a very faint number or two but i cant make it out, however, the engine identification number behind the PS pump tells me my motor was assembled on the 12th December 72 (block was cast 27th Sept 72)and my fender tag date tells me my car was made on the 18th Dec 72, so there is a fair bet the VIN number will match,,,,,, I hope.