Did you know Chevrolet built a high-revving 302 Semi-Hemi small-block that spun past 8,000 RPM?

By the end of this ride, you will. Back in 1968, Ford was coming with the Boss 302, and Chrysler owned NASCAR with the 426 Hemi. Chevrolet’s skunkworks engineers teamed up with Daytona outlaw mechanic Smokey Yunick to build a forbidden weapon: prototype canted-valve hemispherical aluminum heads, dual-quad cross-ram induction, and over 500 naturally aspirated horsepower out of just 302 cubic inches.

Only a handful of these experimental prototype heads ever left the foundry. When the bean counters in Detroit looked at the cost to homologate and mass-produce them for the public, they pulled the plug and buried the project.

Strap in with Raven, listen to the dyno rumble, and discover the wildest small-block Chevy ever tried to hide from the rulebook.