Chevrolet introduced its 327 cubic inch small block as an option for its full-size cars and station wagons for the 1962 model year. To create the 327, Chevy used the same small block design based on the 4.40-inch cylinder spacing as previous SBC engines. However, engineers increased the cylinder bore diameters to 4.00 inches and used a new crankshaft with a longer, 3.25-inch stroke. The base 327 made 210 horsepower using a two-barrel carburetor and an exhaust system that forced both cylinder bank exhaust manifolds into a single restrictive pipe.
Other versions of the 327-cubic inch SBC with 250-, 300-, and 340-horsepower ratings were used in Chevrolet vehicles such as Malibu, Impala, El Camino, Chevelle, and Chevy II between 1962 and its discontinuance from production usage in 1969. These 327 versions used 10.5:1 or 11.25:1 compression ratios, four-barrel carburetors, and free-flowing dual-exhaust systems to achieve horsepower gains and up to 360 lb-ft of torque.
From 1962 to 1965, Chevrolet produced the highest-horsepower 327 engines for the Corvette. Those performance-oriented 327 versions produced between 365 and 375 horsepower, depending largely on which rating Chevrolet felt would sell more cars and the type of fuel induction system they used: Holley four-barrel carburetors or Rochester fuel injection. For example, the 1964/1965 Corvette 327 used 2.02-inch diameter intake valves (compared to the 1.94-inch intake valves used previously). However, it was still rated at the maximum 375 when equipped with the Rochester fuel injection system or 365 horsepower with the Holley four-barrel carburetor.
