The 'cylinder' wars between Chevrolet and Chrysler go back almost to the beginning of production automobiles in the US.
By the 1920's, both of those companies, as well as most auto companies in total, were making four- cylinder cars (luxury and limited production vehicles excepted). Ford's Model T, made from 1909 until 1927, was by far the most produced car in the world, and would remain so until the 1980's when the Volkswagen Beetle finally surpassed it in production numbers. Still, by the end of the run, the T was badly dated and sales were dwindling, so Henry Ford decided to bring out the next model, a particular favorite of his and actually called "Henry's Lady", the Model A. This new and very popular model was introduced in 1928 and was expected to have a long run, as the Model T did but everything changed when Chevrolet came out with the in-line six and the advertising slogan 'a six for the price of a four', and that was the first year that Chevrolet ever out- sold Ford (1929). As the story goes, an enraged Henry Fork remarked 'If it is cylinders they want, it is cylinders they will get!' and immediately began work on what we know today as the Ford Flathead V-8 that would go on to power Ford autos for decades. Of course Chevrolet responded much, much later, in 1955, with their own V-8, the 265 cu. in. 'small block', which was again a modern engine with overhead valves. In fact, most people will say that this was Chevrolet's first V-8 but that is not the case.....
Chevrolet actually introduced a V-8 in 1917 to compete with the other, higher- end manufacturers of the day. In fact, this engine, in the 'Model D', was actually very advanced and unlike the 1933 Ford V-8, it had overhead valves, a direct drive rotary distributor and several other futuristic facets. By all accounts, it was a very good design, very robust and reliable and was basically well ahead of its time. Unfortunately, it was also expensive and the bottom line was that people simply would not pay Cadillac, Pierce- Arrow, Packard, et al. prices for the pedestrian moniker 'Chevrolet'. So the original Chevrolet quietly died a quick death after only two years. Today they are rare and extremely sought- after collector cars.
So the "brand new for Chevrolet" V-8 of 1955 was actually almost 40 years later than Chevrolet's real 'first' V-8.
Brian