Cadillac 331 series V8 engine

The Cadillac 331 series was the company first overhead valve V8, introduced for 1949 alongside Oldsmobile Rocket engine and following the overhead valve layout pioneered by Buick. Bore and stroke of 3.8125 by 3.625 inches gave 331 cubic inches, about 5.4 litres. It had a lighter skirtless block with a partial integral cast iron clutch housing, a dry intake manifold with open runners, a rear mounted distributor and shaft mounted rockers, and its lifters were fed oil through small bleeds as in the Oldsmobile engine. Racers often swapped in solid lifters and adjustable rockers from the Studebaker V8. Displacement rose to 365 cubic inches for 1956 with a four inch bore, rated 285 to 310 horsepower in base form, and to 390 cubic inches for 1959 with a longer stroke, rated 325 horsepower.