4 Barrel on a stock slant

My 1966 GTO came with the AFB type in post #43. Mixture screws plus the large brass centre screw which admitted air to adjust idle speed. Notice there is no idle speed screw; the primary t/blades bottomed out in the bores & speed was adjusted via the brass screw.

Post #41. No 500 cfm AVS carbs, only 500 AFBs.