No matter how you cut it, 454 cubic inches — roughly 7.4 liters — is a whole lot of engine, and it made for outrageous power in the 1970 Chevelle 454 SS. While its base power was already impressive at 360 horses, the LS6 upgrade made for an easy leap to a totally bonkers 450 ponies. This car, and the engine it held, basically represented the limit of the muscle-car power wars, and it is still the highest-output production car to date.