Need some info on what this manifold is from?

Seeing this, I would have to agree with you. So, I don't remember my '69 340 intake having larger secondaries, did it? Or has the pictured manifold had its secondaries altered ? I ran a 440 AVS on my 340 with the stock intake manifold, the 440 secondaries are larger, but if you opened the throttle , it would just align itself. Oh well, just saying.
Thanks