The Chevy Big Blocks W series, evolving into the Mark IV, might be the best V8 ever—just don’t tell the small blocks. Nicknamed the “rat motor” by GM insiders, this engine is a beast at 685 lbs. Its revamped valve configuration and “porcupine design” improve power at high rpm, making it perfect for racing. Despite its serious power, it’s got a playful side, borrowing bits from its “W” predecessor like the Moraine aluminum bearings and side oiling system. It’s the engine equivalent of a heavyweight champ with a sense of humor.