What is a Pontiac 455 engine bored 40 over called?

A Pontiac 455 engine that is bored 40 over is commonly referred to as a "455 +.040." This designation indicates that the engine's cylinders have been bored out an additional 0.040 inches, increasing its displacement slightly. This modification can enhance performance by allowing for more air and fuel to enter the combustion chamber. However, it's important to ensure that the engine components are compatible with this increase in size for optimal performance and longevity.