What is a 318 engine bored 040 over?

A 318 engine bored 0.040 over refers to a Chrysler 318 cubic inch V8 engine that has been modified by increasing the diameter of its cylinder bores by 0.040 inches. This modification increases the engine's displacement slightly, typically resulting in improved performance and power output. Boring the engine allows for the installation of larger pistons, which can enhance engine efficiency and combustion characteristics. However, it is important to ensure that the engine block is still within acceptable tolerances to maintain reliability.