The 1971 & 1972 Formula 455HO & Trans am were real beasts and quite a value compared to the 73 SD's. Under 100 72 Formula 455 HO, with 4spd built. The formula was a real sleeper, especially with steel wheels, caps, no stripes and sans a spoiler. They were comparable in performance to the better known marques built in the late 60's and handle extremely well.
https://www.youtube.com/watch?v=8guIW-2_8PU