third hole in slider?

Hello, Ive got stock carbs on my 1974 Z1. I noticed inside the throttle slider has three holes inside (not including the center hole for the needle). When I disassembled them, the two larger holes were used by screws holding down the throttle plate. The throttle plate has a third hole as well, but the way the throttle plate and lever need to be installed, the holes are opposite each other. are these carbs assembled correctly? What is this third hole for and should it align with the throttle plate??