We have four E Bodies here at my house. Sept 70 built 1971 Challenger has the 70 style floor pan. Nov. 70 build, both 1971 Cudas have the 70 or first generation floor pan. June 71 built 1971 Challenger has a 72 Style second Generation style floor pan. The main difference between the two pans is the shock access hole location,there are other differences also.