From Ford press: Mustang sales passed the one million mark in March of 1966. The 1966 Mustang was the first – and perhaps the only – car to park on the 86th floor observation deck of New York’s Empire State Building. Ford engineers disassembled a 1966 Mustang convertible and took it up in four sections using the building’s passenger elevators.
Mustang-mania hit full force. The 289-cid V-8 “Hi-Po” engine became available. Carroll Shelby adapted the Shelby GT350 for Sports Car Club of America (SCCA) competition, and the GT350 went on to win three straight SCCA national championships.