Meet 4 People Behind the Muscle Car Era: A Newcomer’s Guide by Jack Harmon In the fall of 1963, a 38-year-old Pontiac engineer quietly broke a General Motors corporate rule by dropping a 389-cubic-inch V8 into a mid-size Tempest. GM expected to sell about 5,000 of the resulting cars. Share this: Share on Facebook (Opens in new window) Facebook Share on X (Opens in new window) X