If you want speed with attitude, it’s hard to beat an American muscle car. Technically speaking, a muscle car has a big block V8 stuffed into an intermediate coupe, but like “sports car,” the definition of muscle has evolved to include small block V8s, pony cars, and even sedans and wagons. Without further ado, here are the top ten highest horsepower classic US muscle cars in no particular order.
1974 PONTIAC TRANS AM 455 SD
What had started in 1964 with the GTO, was largely over by 1974. The Goat was pathetic, the Chevelle was hideous, and the Mustang was an economy car without a V8. The ’74 Trans Am was the last muscle car for a long time. Seemingly out of nowhere, the TA received what was essentially a detuned race engine. The 455-SD had a stronger block, forged internals, higher flowing heads, and the capability for dry sump oiling.
While it was dumbed down to 290 hp (and 390 lb/ft) for the street, the modding capability of the SD is extreme. Internal testing showed that with just a cam and better airflow, 530 horsepower was entirely possible.