The 1964 Pontiac GTO used a 389 V8 as its standard engine. Pontiac created the GTO by adding a performance package to the compact Tempest-based LeMans, and the 389-cubic-inch V8 gave the new model its muscle-car character.
The base GTO engine used a four-barrel Carter AFB carburetor, dual exhaust, and a rated 325 horsepower. Buyers could upgrade to Pontiac’s Tri-Power setup, which used three two-barrel Rochester carburetors and raised output to 348 horsepower. A four-speed manual and automatic transmission were also available.
The 389 is often confused with later Pontiac engines. The 421 V8 was a larger high-performance option in Pontiac’s full-size cars, while the 400 V8 replaced the 389 in the GTO for 1967. The 326 V8 belonged to Pontiac’s smaller-engine lineup and was not the standard 1964 GTO powerplant.
The GTO’s combination of an intermediate-size body and a large-displacement V8 helped establish the template for the American muscle car.