The choke was for cold starting conditions and the throttle would hold the engine rpm at any desired level. The long intake manifold on the inline six made the engine "cold blooded" and required a richened fuel/air mixture till warm. The choke could set how rich the fuel mixture was. For cold starting you pulled the choke all the way out till the engine fired and then slowly pushed it back in as the heat built up. If you wanted to go back in the house till the heater got working you had the choke about half way and set the throttle so the engine run fast enough to keep from dying. The throttle should NEVER be used for cruise control. After hand chokes they went to automatic chokes and now to computers.
