September 30: LEMON manuals is back up on a temporary server! Slowness is possible
Orifice Spark Advance Control: Operation
Vacuum is obtained by a vacuum tap just above throttle valves of carburetor. This type of tap provides no vacuum at idle, but provides manifold vacuum as soon as throttle valves are opened slightly. Proper operation requires air tight fittings.
Courtesy of CHRYSLER GROUP, LLC