ORIGINAL: cutaway
Not the newer 6 bolt backplate, this is 4 bolt with a tall smallish venturi. Good? Bad? Never saw one in 30 years, but I have access to a brand new one.
This is the George Aldridge designed fox 40 "big case" I have one, they take a long time to break in. It is powerfull, and I need to find a muffler for it. They run a little fast, but great for a sport model. Problem is the mouinting patern fits nearly nothing modern.