Mustang Boss 429
The Mustang Boss 429 is one of the most valuable and least-common of all muscle cars. There were only 859 made; the Boss 429 came about because of Ford's desire to build a Hemi engine that could compete in NASCAR with Chrysler. NASCAR rules required that at least five hundred production models be sold to the public, and after careful consideration, Ford decided to shoehorn the giant motor into a Mustang.
The 429 came from Ford's 385, but the Mustang's body wasn't wide enough to hold the engine, so Ford contracted with Dearborn's Kar Kraft to modify the bodies of Mach 1s to accommodate them. At the time, Kar Kraft was also busy building the Boss 302. Boss 429 production began in 1968 in Michigan, and the cars were taken directly from Ford to the plant. There were extensive modifications made to the Mustang, such as widened shock towers and extended inner fenders.
Front suspension mounts were also displaced in order to make room for the exhaust manifold and block. The battery was moved to the trunk and a stout sway bar was added to the car's rear end. A hole was cut into the hood and a manually-controlled hood scoop was added. The Boss 429 was rather conservatively rated at 375hp, but they put out well over 500hp in reality.
Both model years had a less-flashy exterior; the only badging was on the front fenders. All Boss 429s were given special identification on the driver's side door. Sales began to decline in 1970, and due to rising production costs, fuel prices and internal issues at ford, that was the last year the Boss 429 was produced.