Here are the essentials.... The 265 and 283 3-inch-stroke, small-journal crank has a perfectly round flange. The rare 1967 Z/28 302 3-inch-stroke crank has a round flange with one notch.The 265 and 283 3-inch-stroke, small-journal crank has a perfectly round flange. The rare The cylinder heads used through mid-1959 have a staggered valve-cover mounting pattern. The 1955-1957 265 and 1957-only 283 blocks have no side motor mount provisions. The 283/283hp fuel-injected engine was among the first of the American engines to dispense with carburetion and make 1 hp/ci. Under legendary Corvette engineer Zora Arkus-Duntov's tutelage and encouragement, a slew of factory and aftermarket parts were developed for the 283. With a large variety of parts available, it became easier and cheaper to coax horsepower out of a Chevy small-block than the competition's engines. More enthusiasts gravitated toward the "easy to work on" Chevys, which encouraged the development of even more parts--and so the Chevrolution became self-feeding. Even after the 327’s debut, the 283 made such a good base engine that it soldiered on through 1967. With its short 3-inch stroke, a 283 can rev as if there’s no tomorrow, but the small bore restricts adding really large valves and, hence, ultimate breathing potential. Except for the Vette 283/315hp option, 283s never came with anything larger than 1.72-/ 1.50-inch valves. You can install only 1.94/1.60 valves without hitting the cylinder walls. The 1.9:1 rod/stroke ratio is on the high side for an acceleration engine but great for an endurance or oval-track engine that runs at a high, constant speed. However, there’s no getting around the fact that a 283 just gives up too many cubic inches (and too much torque). Unless you’re into nostalgia, restoration, or class racing, there is no real reason to build a 283 today. SOURCES Valley Head Service (VHS) Northridge CA Enjoyed this Post? Subscribe to our RSS Feed, or use your favorite social media to recommend us to friends and colleagues!