The 1973 Mustang was the last of the big Mustangs. The body was unchanged from the last two years except for minor changes to the grille. The Mach 1 was the performance model however due to emissions the 351 cleveland 4bbl only had roughly 156 net hp which is lower than gross. A 1971 Mach 1 was the star of the 1974 movie Gone in 60 Seconds although the car was meant to portray a 1973 Mach 1 in a 40 minute police chase. All in all I think this was the last of the real Mustangs.