The Camaro/Mustang rivalry had begun in 1967 with the introduction of the Chevrolet Camaro by General Motors. The Camaro was the largest threat to the lead Ford had in the "pony car" field, a market segment largely created by Ford with the introduction of the Mustang in midyear 1964. The performance of the Mustang with 289 and 390 engines was not up to the Camaro, with its small block and big block V8. In an effort to improve the Mustang's image, Ford made optional the 428 Cobra Jet V8 in midyear 1968, and in 1969, the Ford Boss 302 engine. The 302 was a composite engine using the "tunnel port" Windsor block and large Cleveland heads. This optional engine was available for the express purpose of meeting the homologation guidelines to compete in the TransAm series.
The Boss 302 Mustang was designed by Larry Shinoda, a former GM employee. The car featured reflective "cstripe" and the fake rear fender scoops of the regular 1969 Mustangs was eliminated. Optional were black horizontal rear window shades and a blackout hood. It was one of the first production models with a front spoiler and rear deck wing. The name "Boss" came about when Shinoda was asked what project he was working on, he answered "the boss's car" because the project was a secret.[3] Also Shinoda had called it the "Boss" as an homage to the new President of Ford Semon "Bunkie" Knudson who had brought Shinoda over from GM when Knudson had left.
Changes for the 1970 model year included side "hockey stick" stripes which started along the top of the hood, along with the 1970 grille which replaced the 4 headlights with two vents in the outside position while retaining dual headlights within the grille opening. The dual exhaust system was redesigned, along with the competition suspension and a standard Hurst shifter. The intake valves were smaller, and aluminum valve covers replaced the chrome. With a suggested price of offered for $3,720, a total of 7,013 were sold.
Standard were disc brakes on the front, larger sway bars,a lower ride height, heavier duty spindles, reinforced shock towers, a four speed manual transmission, and the solidlifter Boss 302 V8 engine with its freebreathing Cleveland style heads, which had valves larger than most motors over a third larger in displacement. This "G Code" engine was rated at 290 hp however modern day tests show the engine may have been largely underrated, with dyno's showing in excess of 380 horsepower in some cases.
The 1970 car could accelerate from 060 mph (97 km/h) in 6.9 seconds. The quarter mile took 14.6 seconds at 98 mph