How much horsepower does a 307 Chevy engine have?
The 307 Chevy engine does not have a single fixed horsepower figure. It varied by model year, application, and configuration, but most versions from the late 1960s to early 1970s produced roughly 180–210 horsepower, with lower figures in the late 1970s and 1980s due to emissions controls and detuning. The exact number for a given engine depends on carburetion or fuel injection, compression, camshaft, exhaust, and how the horsepower was rated (gross vs. net).
What determines a 307’s horsepower
Several factors influence the reported horsepower of a 307 cubic-inch small-block Chevrolet. Differences in compression ratio, cam timing, intake and exhaust systems, carburetion or fuel delivery, and the rating method used by Chevrolet at the time (gross horsepower in the 1960s vs. net horsepower introduced in the early 1970s) all affect the final figure. The 307 was used across various cars and trucks, often as a lower-emission, torque-oriented option, so its power output varied widely between configurations.
Why the numbers vary across years and models
Because GM updated engines and rating methods over the years, the same displacement could show different horsepower in different catalogs. Early 307s tended to show higher (gross) numbers, while later 307s commonly show lower (net) numbers after emissions regulations and changes in testing practices. Car vs. truck applications and two-barrel vs. four-barrel carburetion also played a big role in the final horsepower figure.
Typical horsepower ranges by era
The following ranges illustrate how horsepower for the 307 generally varied, depending on year, configuration, and rating method. Note that these are approximate figures intended to provide context rather than a precise specification for every engine.
- Late 1960s car applications (often four-barrel, higher compression): about 190–230 horsepower gross (lower when rated as net by later standards).
- Early 1970s, post-emissions adjustments: roughly 150–190 horsepower net, depending on tuning and equipment.
- Mid to late 1970s, tighter emissions and detuning: typically 140–180 horsepower net.
- 1980s, trucks and some cars with milder specs: commonly around 150–180 horsepower net, with some variations higher or lower depending on configuration.
In practice, the exact horsepower for a specific 307 depends on its exact build date, body application (car vs. light truck), and how its power output was measured and published. If you need the precise figure for a particular engine, check the build sheet or factory literature for that VIN/engine code, or verify with a dynamometer test under the intended conditions.
How to verify the horsepower of a specific 307
To determine the exact horsepower of your 307, consider these steps or checks:
- Find the engine code stamped on the block or intake; cross-reference with Chevrolet documentation for that year and model.
- Identify whether the original rating would have been a gross or net figure based on the production year.
- Review the factory build sheet or RPO/option codes to confirm carburetion, compression, and cam configuration.
- If possible, have the engine tested on a dynamometer to establish current horsepower under controlled conditions.
Understanding these details will give you a more accurate sense of the engine’s current power output, especially if the engine has been rebuilt or modified since it left the factory.
Summary
The horsepower of a 307 Chevy engine is not a fixed number. It depends on year, application, and configuration, with common ranges spanning roughly 140–230 horsepower across the era, and typical values around 150–200 horsepower for many late-1970s to 1980s builds. To know the exact figure for a specific engine, consult its build documentation, engine code, or perform a controlled dynamometer test. In short, context matters: age, rating method, and configuration all shape the final horsepower.
How much horsepower does a 1972 Chevelle 307 have?
130
The 1972 Chevelle series became America's second-best-selling car. Base versions again included a four-model wagon series. Upscale versions were Malibus, including convertibles. More than 24,000 Malibu Sport Sedans were built, with a standard 307-cubic-inch V8 rated at 130 (net) horsepower.
Is the Chevy 307 a good motor?
The Chevy 307 is a good, reliable engine for period-correct restorations, comfortable street use, and mild hot-rodding, but it is not the ideal starting point for high-performance or high-displacement builds. Choose it when you value drivability and authenticity; choose a 350/LS/etc.
What is the difference between a 305 and 307 engine?
The Chevy 307 was made from 1968 through 1973 and it was a 3–7/8″ bore engine with a 3–1/4″ stroke. The Chevy 305 made from 1976 through 1998 was a 3.736″ bore engine - slightly smaller than the 3.875″ of the 307, but a 3.48″ stroke.
What years did Chevy use the 307 engine?
An economy 307 cu in (5.0 L) version was produced from 1968 through 1973 as Chevrolet adjusted to increasingly stringent federal emissions standards. Engine bore and stroke was 3.875 in × 3.25 in (98.4 mm × 82.6 mm).
