Quote:

see the "AFB QUESTION" thread further down. QuickD100 posted CFM's for the diff venturi sizes which'd very likely be the same for OE type AFB's/AVS's. EDIT those are base plate throttle bore dia's. I just checked my 4131S AFB which is listed for a '66 440 & it's 1&7/16" & 1&9/16" which'd be (750) but I think Carters' published specs are a bit happy



I posted the venturi diameters for their carbs, the throttle plate diameters are not the same as the venturi diameters, case in point.
The 500's and 625's both use 1-7/16 promary throttle plates, the secondaries throttle plates measure 1-11/16 on both.
The info comes out of Dave Emanuel's "Super Tuning and Modifying Carter Carburetors". Dave