Boss 302 History & Development

The legendary Boss 302, known as the Ford Boss 302 Mustang, may not be what everyone thinks it is. While, yes, it is a car, this particular car was made for a particular motor. The original Ford Mustang car came first, manufactured April 17, 1964 and it was not until after the Boss 302 motor was manufactured in the Mustang ‘s (April 17th) 1969 model year that a particular Ford Mustang was named after it, the Ford Boss 302 Mustang to be exact. The Boss 302 motorwas manufactured and introduced as a direct retaliation to the Chevrolet Camaro z28’s win in the 1968 Sports Car Club of America (SCCA) Trans-American (Trans-Am) Sedan Racing series(Farr, 2000).

It was because of this championship series that the consumers of the world became lucky in the years 1969 and 1970; after Ford was made to abide by the rule of the SCCA that stated that any car to race in the series must be sold to consumers as well. Because of this rule,Larry Shinoda, formerly of General Motors, designed the Ford Boss 302 Mustang car to be fitted around the engine. If it were not for this rule, the legend of the Boss 302 Mustang would not exist today.

Boss 302 Engine Specs

The Boss 302 cubic inch small block V8 motor was made by taking the heads from the Ford Cleveland (manufactured in 1970) and adding them to the 4 bolt heavy duty block of the Ford Windsor (manufactured in 1962). The design of the heads themselves are called “tunnel-port” because of the way the pushrod runs a straight path through a round intake port in its center therefore flowing better(The Ford V-8 Engine Workshop). The tunnel port design was used on the 427 FE first then was later adapted for the Boss in 1968.

The heads of the Cleveland were arranged in canted-valve staggered style in order to allow for the extra room needed. The Boss 302 used intake valves that were 2.23 inches diameter and Exhaust valves of 1.72 inches diameter in 1969. In 1970, the intake valves were 2.19 inches diameter and the exhaust valves of 1.72 inches diameter. These heads also featured steel spring seats, adjustable rocker arms, screw-in rocker studs andpushrod guide plates and these head features were actually used on the Boss 302 before the Cleveland was officially developed or introduced to the public(Begley, 2002).

The Boss 302 stock mechanical camshaft had a high lift and long duration using a solid lifter with an automatic acceleration rate of 2.47. It features intake duration of 290 degrees with an intake centerline angle of 111 degrees and Lobe centerline angle of 116.0. The exhaust duration is 290 degrees with an exhaust centerline angle of 121 degrees and the valve overlap at 58 degrees.

Other specs for the Boss 302 from 1969 to 1971 (Begley, 2002) are as follows:

  • Bore and Stroke: 4.004 inches by 3.0028 inches (1.1.6 mm by 76.0 mm)
  • Compression Ratio: 10:5:1
  • Maximum Horsepower: 290 BHP @ 5800 RPM
  • Maximum Torque is 290 pounds per square foot @ 4300 RPM

The Results

The final creation was a hybridized small block 302-ci V8 motor that weighed in at over 500 pounds. It was more powerful and could out perform the Camaro z28-and finally did in the 1970 series championships(Farr, 2000). The Ford Boss 302 Mustang racing version only came in a four speed manual transmission. The Boss’ body is a version of the SportsRoof without the simulated side scoops.

The 1969 version was only available in four colors, “Wimbledon White,”“Bright Yellow,”“Calypso Coral” and “Acapulco Blue” and it came with a variety of interior colors. However, black was used in most cases. The 1970 was available in “Grabber Blue,”“Grabber Orange” or “Grabber Green,” “Calypso Coral” or “Pastel Blue” with either a black or white interior. The 1970 version had a redesigned exhaust system and suspension and aluminum valve covers replaced those of the 1969 model. The boss 302 was finally retires and replaced with its successor, the Boss 429 in 1970 (

Works Cited

Begley, D. (2002, May 06).
Ford 302 FE V-8 Engines. Retrieved April 02, 2010, from Car Memories:

Farr, D. (2000, June 20).
The Boss 302 Story. Retrieved April 02, 2010, from (n.d.).
The Bosses > 1969 Boss Mustang. Retrieved April 09, 2010, from

The Ford V-8 Engine Workshop. (n.d.).
Tunnel Port 302. Retrieved April 02, 2010, from The Ford V-8 Engine Workshop: