Only 71 Dodge Challengers left the factory with the fearsome 426 Hemi in 1971, the engine’s final year of production. Rated at 425 horsepower, the 7.0-liter V8 turned an already muscular coupe into one of the rarest performance cars Detroit ever built. Seeing one still doing burnouts and donuts instead of sitting in a climate-controlled garage is a genuine treat for muscle car fans.