How much horsepower does a 1958 Chevy 348 have?
The short answer: horsepower varied by carburetion and trim—from about 250 hp in the base two-barrel configuration to roughly 320 hp in the top Tri-Power setup.
In 1958 Chevrolet introduced the big-block 348 cubic-inch V8, known as the W-series, which powered a range of passenger cars and trucks. The horsepower figures from that era were published as SAE gross ratings, which measure engine output before accessories are added. Because of different carburetion, compression ratios, and body styles, the exact number depended on the specific configuration.
Configurations and horsepower
Here is a snapshot of the typical configurations available in 1958 and how they translated into horsepower:
- 348 Turbo-Fire with a two-barrel carburetor: approximately 250 horsepower (gross).
- 348 with a four-barrel carburetor: roughly 270–290 horsepower (gross).
- 348 Tri-Power setup (three two-barrel carbs): around 315–320 horsepower (gross).
Notes: The figures above reflect the gross horsepower ratings used in 1958. Modern restorations or dyno tests may report different numbers depending on how the engine is rebuilt, measured, or equipped with aftermarket parts. For precise identification, the engine code and the car’s trim level can help confirm which configuration applies.
Measuring horsepower then vs now
Back in 1958, horsepower was typically published as SAE gross output—engine-only power measured without belts, alternators, and other accessories. Today’s ratings usually reflect net power, which accounts for those components and typical wear. That difference means the same engine can appear to produce different horsepower when viewed across eras, so context matters when comparing figures from old brochures to modern specs.
Why the numbers vary across models
Different body styles and market niches—ranging from sedans to light-duty trucks—often used different exhaust, cam profiles, and compression setups. While the core 348 block was shared, small changes in carburetion and tuning could shift horsepower by several tens of units. If you’re researching a specific car, checking the engine code plate, VIN, and original dealer documentation will give the clearest answer.
Summary
In 1958, the Chevrolet 348 V8 offered a spectrum of horsepower from about 250 hp (base two-barrel) to roughly 320 hp (Tri-Power), with intermediate figures for four-barrel configurations. The exact rating depended on carburetion, compression, and the model, and readers should remember that era-specific gross horsepower figures differ from modern net ratings. For collectors and restorers, identifying the correct configuration through engine codes and factory paperwork is key to pinning down the precise horsepower of a given car.
