Just for info, AFB's had a 4 1/4 diameter for the air cleaner. Those carbs aren't AFB's. They look like carbs on a GM I owned years ago. they have the 4 3/4 outlet as well, but not an AVS carb, no Air door, as pishta said. AVS carb's had air screws both at a 90 degree, 1969, and 45 degree, 1968.