3418682 was a after market one that Edelbrock made but only a few and went back to the 81 part #. Not sure what that was all about but I have only seen about 3 of them.
I have one of these that is new. It was bolted on an engine and removed. I also have an OEM one, no real difference other than the markings.
The 6 pack intakes are bringing around $800 from what I have seen lately. New in box will bring a couple hundred more I would imagine.
