From the FSM

Checking Bowl Vent Valve Clearance
To check the bowl vent valve clearance
adjustment, proceed as follows:
(1) With the throttle valves at curb idle, it should
be possible to insert a .015 in. gauge between bowl
vent valve plunger stem and operating rod, (Fig.
26).
(2) If an adjustment is necessary, bend rod to
change arc of contact with throttle lever