While researching info on my MaxWedge project I noticed this: 3447 verse the later 3705......... they are quite different. Both used during the MaxWedge years. I know later was big airhorn/base. BUT that's not the kicker........the later "Competition" - "Series 9000" - "Edelbrock" stuff is totally, 100%, not the same to my eye..........as the AFB's I see on Max Wedge/Chevy 409/Cadillics etc. Just how many AFB's are there and what's the history? I don't need model number - date stamp - specifics.............just a little info. Seems like there's about three totally different bodies and multiple different tops. The three look like completely different carbs to me...................like a '64 Impalla verses a 2014 Impalla.....only the name carries on, not the same car.
Don't know how many. But there is a bunch. Air horn size, fuel inlet location, linkage arm style, idle adjustment screws. Choke assy. or not. Choke plate or not. Even seen some Lincolns that look to have vacuum secondaries. 3447's and 3705's from the outside differ mainly by air horn size and fuel inlet location. If I remember right 3447's have the third idle air screw. They both do have a linkage arm for that application.
You're asking "how high is up?". An open-ended question like that has no answer. The AFB has been made in dozens of variations for dozens of OEM and aftermarket applications by at least three corporations over a 50+year span. Some get picky and try to differentiate the small airhorn Carter AFB from the large airhorn Carter AFB from the Weber and Edelbrock AFB and Thunder series, but that would take a book. Wait a minute, at least two guys have written books, so buy the books: Rebuild & Powetune Carter/Edelbrock Carburetors... by Larry Shepard Published by HP Trade In 2010 How to Rebuild and Modify Carter/Edelbrock Carburetors by Dave Emanuel, 2007 jack vines