For the 1966 Corvette, the new 427 big-block engine came in two forms: the relatively mild L36, which featured a hydraulic-cam and produced 390 horsepower on 10.25:1 compression, and the truly awesome L72, a 425 horsepower engine with 11:1 compression, larger intake valves, a bigger Holley four-barrel carburetor on an aluminum manifold, mechanical lifters, and four-hole (instead of two-hole) main bearing caps.
