5. Cadillac 500 V8
The Cadillac 472 was an enormous, potent engine when they introduced in 1968. However, GM’s top luxury brand wanted more. So just two years later, the company introduced the mighty 500 V8 with the biggest displacement in the world.
At first, the new engine was exclusive to the Eldorado coupe. But after 1975, it was available in Fleetwood sedans and limousines, and the De Ville, as well as the commercial chassis. The 500 V8 produced 400 HP for 1970 and an astonishing 550 lb-ft of torque. Unfortunately, this engine was also affected by emissions regulations and low compression. Gradually, it lost power to the point where the once-mighty Cadillac 500 V8 only produced 190 HP. They ceased production in 1977.