All automatic chokes use a bimetal strip to close the choke plate. The difference is in where they get the heat to release the spring. Conventional chokes pull air past the exhaust manifold and heat the spring with the hot air. Electric chokes have a resistance wire coil in the choke cover and use electric current to provide the heat to release the choke plate. If you use the electric model, you'll need some sort of switching device to turn it on and off in case the engine stalls during warm-up. Otherwise, the choke will release fully before the engine gets warm, and it will be hard to restart. Factory electric chokes use an oil pressure switch, or a wire from the alternator stator which is only hot with the engine running. What carburetor do you have? Some carbs do not have an electric option available, such as the older Rochesters and Carters.
Jerry
