There are only 3 adjustment screws.
The GAV is the main adjustment and this things run best with it turned out from lightly seated at about 1/2 to 3/4 turns. The GAV is also the choke rod.
The idle speed adjustment is the little screw that sets the the throttle plate.
The idle mix adjustment is the little screw in the front the carburetor barrel/venturi and is an air adjustment.
would the idea screw be the top one?