Chevrolet 307 Engine Specs

The Chevrolet 307 is a naturally aspirated OHV V8 petrol engine produced from 1968 to 1973, developed as a mid-displacement small-block variant positioned between the smaller 283/302 engines and the larger 327/350, used primarily as a mainstream, torque-focused engine across the Impala, Chevelle, Nova, and Caprice rather than as a performance option.

Producing 200-220hp and 407Nm of torque from 5,030cc, the 307 uses the familiar OHV 16-valve small-block architecture with a compression ratio of 8.5-9.0:1, tuned for smooth, low-stress everyday driving rather than outright performance - it was never intended to be Chevrolet's sporting engine, and instead served as a dependable, moderately powerful option for family sedans and wagons during the muscle-car era, when many buyers still wanted straightforward, low-maintenance V8 power rather than outright speed.

As with the rest of the small-block family, the 307 benefits from a fundamentally simple, well-understood design and an enormous aftermarket that continues to support these engines decades after production ended. Reliability is generally good when properly maintained, though as with any engine now more than five decades old, age-related wear is the primary consideration for any prospective buyer: timing chain stretch, bearing wear, and general seal and gasket deterioration should all be assessed on a used example, along with the condition of the cooling system, which has had many decades to accumulate scale, corrosion, or previous poor-quality repairs. Because the 307 was never a high-performance or particularly desirable engine even in period, surviving examples are less commonly kept in fully original, numbers-matching condition than more prestigious small-block variants, and many Chevelles, Novas, and Impalas originally fitted with a 307 have since been upgraded with a larger or more powerful small-block as part of restoration or restomod projects - worth being aware of if factory originality matters to you as a buyer.