'68 Bronco 2100s are equipped with a manual choke. '70 2100s have a diaphragm type de-choker that replaced the piston type on earlier 2100s, that had automatic chokes. No real advantage to either type. Your decision is choosing between an auto or manual choke. Autolite and Motorcraft carbs are made in the same place by the same people. Ford just stopped using the name Autolite.