What is a sbc 305 bored 40 over called?

A SBC 305 bored 40 over refers to a small block Chevy 305 cubic inch engine that has been bored out by 0.040 inches, increasing its displacement. This modification typically brings the engine's total displacement to approximately 316 cubic inches. Such modifications can enhance performance by allowing for greater air and fuel flow, resulting in improved horsepower and torque. This engine configuration is commonly referred to as a "306" or "SBC 306."