In 1949, Cadillac and Oldsmobile introduced revolutionary modern overhead valve V8 engines, with more power but lighter and rev’d higher, making their competitors’ engines obsolete. They also had the benefit of the GM HydraMatic automatic transmissions that were the best of their type for a generation. Here are details on the Oldsmobile Rocket engine.  The 1949 Rocket 88 was the pace car at the Indianapolis 500 and tore up the stock car circuits. This car is at Custom Car Crafters, link at right.