The L88 427 was Chevrolet’s most brutal engine of the muscle car era, and it never once appeared on a factory Camaro order sheet. This 1968 SS/RS wears one anyway, the product of a dealer tradition that turned Corvette-only horsepower into a street-legal secret weapon. Here’s the real story behind an engine GM rated at 430 horsepower that everyone in Detroit knew made closer to 570.