The townships now in existence and those to be created are divided into two classes: townships of the first class and townships of the second class. A township of the first class shall be a township having a population of at least 300 inhabitants to the square mile and is functioning as a township of the first class on June 24, 1931, or that were created after June 24, 1931, as a township of the first class in the manner provided in this act. A township that is not a township of the first class or a home rule municipality shall be classified as a township of the second class. A change from one class to the other shall be made only as provided by this act or the laws relating to townships of the second class.
53 P.S. § 55201