To make sure its a 440, check the pad the water pump sticks out of, below the head. A 440 is a raised block, this pad will be below the head gasket surface. A 383 low-block has this pad at the same height as head surface, so it's machined. A 383 stamp will be found on it, too, I believe. A 440 will have a 440 stamp on the pad ahead of the intake, on the valley surface. As far as it being "THE"440, that came in the car, you'll have to find the engine serial #. Can't help ya there, I never was one to worry about such niceties.