1969 Ford Mustang Boss 429 Fastback - $357k

KK no. 1358. Royal Maroon over black. Extensive restoration with 16 miles since completion. S-code 429 CI V-8 engine. Correct HP block and early-style intake. Correct carburetor and distributor. Correct RUGAE2 4-speed manual transmission. N case 3.91 rear end. Competition suspension. Power steering. Power brakes with front discs.

859 Boss 429s were produced in 1969. It was Ford's most expensive non-Shelby Mustang offering. MSRP for a new 1969 Ford Mustang Boss 429 Fastback was around $4,798, making it nearly twice the price of a base Mustang. In essence, the '69 Boss 429 was a street-legal race car.

The legendary 429 (7.0L) "Boss" engine was a race-bred "semi-hemi" design with massive ports, aluminum heads, and designed for high RPMs. It featured forged internals and a dry-deck block. The monster engine required significant suspension and chassis modifications for installation, including a widened front track. Rated at a ridiculous 375 horsepower, it likely produced 450+ hp from the factory. Minor modifications (removal of smog pump) pushed that to 500 hp and beyond. Hagerty suggests a councours 1969 Ford Mustang Boss 429 Fastback is trending around $450k. This example appeared at Mecum and hammered for $357k.