The number is magic, recalling the era when Detroit dominated the world with its big, powerful, swaggering V-8s. The Chevrolet 427 V-8 first appeared as an experimental engine that powered Junior Johnson to a then-amazing 166-mph lap at Daytona in 1963. It went into production soon afterward, known variously as the Mark IV, the Chevy big-block, or simply the rat motor. Now the 427 is back, powering the fire-breathing 2006 Z06 Corvette. Okay, so the engine actually displaces 427.6 cubic inches (7008cc), about one more cubic inch than the original. That's because this new 427 is not a reincarnation of...