The muscle-car era officially began with the 1964 GTO. The "goat" established the pattern for a decade of American muscle. Car enthusiasts still revere the 1964 GTO, which commands premium prices at auctions.



Big engines

First and foremost. With few exceptions, muscle cars toted big iron, from the GTO's original 389-cubic-inch V-8 to General Motors' whopping 455-cubic-inch motor.



Four-on-the-floor

Though some legitimate muscle cars had automatic transmissions, most had manual four speed transmissions often moved by legendary Hurst shifters.



Relatively small size

With the emphasis on relative. Many manufacturers dropped big engines into midsize sedans. By today's standards, the cars were big, but they looked lean and mean in the super-sized '60s.



Some define a muscle as; made in the USA between 1964-