In this rare photo, Larry...
In this rare photo, Larry Shinoda is shown at work in the Ford design studio in 1969. The project for this day is the Torino King Cobra, and the drawing on the table depicts a King Cobra decked out in the famous No. 43 paint scheme used by Richard Petty. Shinoda is standing in the middle foreground.
A prominent player in the development of the Boss 302 Mustang styling was Larry Shinoda. Hired away in August 1968 from the GM camp where he achieved fame as the designer of the '63 Corvette Sting Ray, Shinoda was responsible for many of the significant design features found on the Boss 302. These features included the graphics as well as the spoilers and rear-window slats available optionally on the car. At the same time, Shinoda was also the one to remove other design ornamentation features found on the regular '69 Mustang such as the fake sidescoops and roof-pillar horse emblems.
The Boss 302 mill seen here...
The Boss 302 mill seen here has the optional shaker hoodscoop and cast-aluminum valve covers. These features betray this engine as a '70 edition.
For '69, the Boss 302 was available in only four colors: Bright Yellow, Acapulco Blue, Calypso Coral, and Wimbledon White. For '70, most Ford colors were available. In addition to the changes made in the regular Mustang, changes for the '70 model year to the Boss 302 were several. These included the addition of the rear antisway bar, cast-aluminum valve covers on the engine, and smaller intake valves.
Although the Ford Trans-Am effort for '69 ended in frustration, the '70 season saw Ford and the Boss 302 victorious, with the No. 15 car of Parnelli Jones ending up in the Winner's Circle.
This photo dates from the...
This photo dates from the Trans-Am finale held on October 4, 1970. The Mission Bell 200 was held at Riverside, California, and despite heavy damage to his car, Parnelli Jones was still able to take home the gold for Ford to conclude the '70 Trans-Am season. Shown here at speed, Jones had improvised ducting taped to his car at the driver's window to help alleviate the stifling heat of the racing Boss interior. Heat from the engine was compounded by the sweltering late summer typical of Riverside.
The Boss 429 was developed concurrently with the Boss 302; however, its final production was done at Kar Kraft in Brighton, Michigan. The Boss 429 Mustang was designed and offered to the public in order to homologate the 429 engine for NASCAR racing. SportsRoof Mustangs originally produced to receive the 428 Cobra Jet engine were shipped to Kar Kraft for completion. To accept the larger engine, Kar Kraft lowered and moved outward the front suspension. Special spindles and control arms unique to the Boss 429 were used. Outwardly, these special Mustangs were identified by a Boss 429 fender decal. The Boss '9 also came equipped with dual racing mirrors, a front spoiler, a functional hoodscoop, and a trunk-mounted battery. An engine oil cooler, power steering, and front disc brakes were also included. The standard transmission was a close-ratio four-speed connected to a 3.91:1 Traction-Lok rear axle. Magnum 500 wheels sized 15x7 were standard and shod with F60-15 tires. It was a good-looking Mustang although less flamboyant than the Boss 302.
This '69 Boss 302 shows the...
This '69 Boss 302 shows the absence of the fake fender scoops and sail-panel emblems, both found on the standard Mustang. Also seen are the optional and very popular rear spoiler and window slats that were Shinoda's handiwork. This car also shows the Magnum 500 wheels and standard hood, which was the only type offered for the '69 Boss 302. Available in '69 for the 351W and FE 390 engines, the shaker hood became available as a Boss 302 option for '70.
Under the hood, a beefed-up version of the 385-series 429 engine was used. The blocks featured four-bolt main caps and a forged-steel crank. Special-design aluminum heads were used and no head gaskets were employed on the engine. Instead, the cylinder bores were sealed by O-rings. The heads featured a modified hemispherical-shaped combustion chamber referred to by Ford as the "crescent design," and the Boss 429 engine became known as the Blue Crescent 429 in Ford circles.

One look under the hood of...

One look under the hood of a Boss 429 shows why Kar Kraft of Brighton, Michigan, faced a significant challenge in making the 385-series Boss engine fit in the Mustang. The special cylinder heads and valve covers used on the Boss version of the 429 didn't help matters.

The bone-stock '69 Boss 429...

The bone-stock '69 Boss 429 shown here shows how low-key these cars were compared to their 302 brethren. Only the small decal behind the front wheels proclaimed the fact that this car was something special. Notice how, on the Boss 429, the faux sidescoops behind the doors were retained.
In '71, the Mustang was redesigned yet again. Now the car was larger and heavier than ever before. Even the wheelbase was lengthened to 109 inches, up 1 inch from previous incarnations.
To align Cleveland heads with...
To align Cleveland heads with a Windsor block, you'll need to drill three auxiliary coolant holes. Simply place the gasket on the block and mark the locations. Remove the gaskets and drill the correct size hole into the block.
Home-Brewed Boss
Those of you wanting to produce something different might be interested in concocting your own "homemade" version of the Boss 302. The durability of the Windsor block, combined with the flow capacity of the 351 Cleveland heads, either the two- or four-barrel version, can make an interesting and powerful combination. Keep in mind that, in 1969, the Cleveland heads were an advanced design for their time, which featured huge ports and valves. However, they were designed without the tremendous benefit of computer-aided testing. Hence, many of the newer cylinder heads made for the Windsor 302 will give you a more balanced power curve.