Numbers Matching?

I'm considering a seller proclaimed "numbers matching" 72 Demon but I have to be honest, I don't know how to verify it. The only knowledge I have is of a 69 Camaro which has the vin stamped on the rear ledge of the block. Is the vin of a Demon stamped on the engine block? I think this guy thinks that because it's an "H" code and that it has a 340 in it that it is a "numbers matching" car. Doesn't "numbers matching" for a Mopar mean the same as for a Camaro, that it's the ORIGINAL engine?