Cadillac's Series 75 debuted in 1936, hitting the market as a step above the standard Series 60, which itself had just been introduced as the entry-level Cadillac model. The Series 70 and 75 (70 having the shorter wheelbase) featured new, streamlined styling refined by Fleetwood as well as a new monoblock, 346 cubic inch V8\\. The monoblock engine incorporated the crankcase and cylinders in one casting, which was topped by L-type cylinder heads. The new engine was both lighter and more powerful than the old unit, and it was continuously refined until the 331 cubic inch overhead valve engine debuted in 1949\\. The monoblock Cadillac engine was renowned for smooth and reliable running - as well as its power. The US military even adopted a version of it to power the M5 Stuart light tank during WWII. Generally speaking, as the top-line V8 powered cars (the Sixteen was still available through 1940), 70-series cars were equipped with formal bodies, given their upmarket stature and price. As before, Fisher and Fleetwood were the preferred in-house coachbuilders for Cadillac, and a wide variety of styles were offered on this high-end chassis.