Ford Almost Gave Us A BOSS 429 Mid-Engine Mustang, In 1969

The Ford Mustang BOSS 429 We Know

The BOSS 429 Mustang was produced from 1969 to 1970, alongside the BOSS 302. While the BOSS 302 was produced for the Trans Am Racing Series, the BOSS 429 was intended to meet Ford’s need for a 429 V-8 engine homologation for the NASCAR series. . The large V-8 featured a combustion chamber with a semi-hemispherical design, which is why it is often referred to as Ford’s Hemi.

Like other Muscle cars from that era, BOSS 429 engine is underrated. Output is rated at 375 horsepower at 5,200 RPM and 450 pound-feet (610 Nm) at 3,400 RPM. However, independent dyno tests have proven that the engine actually delivers 420 horsepower at 5,600 RPM.

1969 Ford Mustang Boss 429 Specifications
Machine: 7.0 liter V-8
Horsepower: 375 HP @ 5,200 RPM
torque: 450 LB-FT @ 3,400 RPM
0-60 mph: 6.5 seconds
Top speed: 140 mph

Weight Distribution Problem

1969 Ford Mustang Boss 429 Exterior High Resolution - image 683167

429 features forged steel internals capable of delivering more strength in race-trimbut for all its abilities, it has one weakness – weight. Despite having an aluminum head, the Hemi Ford still weighs in at 680 pounds (308kg). This results in a 60/40 weight distribution, where 60 percent of the weight is on the front axle.

Where the Mustang LID Comes in

Ford engineers know 60/40 weight distribution is not ideal for performance applications, according to, Ford turned to its Special Vehicles and Detroit-area skunkworks unit, Kar Kraft, to make the BOSS 429, with a large V-8 in the rear. An entirely new sub-frame was developed for the LID Mustang that will accommodate a 429 cubic-inch V-8, a C6 automatic gearbox, and a nine-inch rear axle, which rotates 180 degrees. The axle itself, converts to independent operation, with an articulated half shaft and a u-joint, as described by

Access to the longitudinally mounted engine is obtained through the rear windshield, which is grilled. The LID still has a rear trunk, at least according to the pictures, but the rear seats have to fit in, to fit the engine in the middle. To top it all off, the LID Mustang uses Koni coil-over shocks and rear control arms. The front area that used to be the engine room now houses the battery, radiator, AC condenser, and electric cooling fan.

What does LID stand for?

The LID moniker stands for Low Investment Drivetrain. Ford wanted to solve the BOSS 429’s weight distribution problem for as little money as possible (or at least try). They used as many spare parts as possible, to build a new sub-frame and move the V-8 and most of the peripheral and drivetrain components to the back of the car. With this in mind, don’t be too quick to compare it to european exoticwhich actually has the budget for research and development.

What’s the Visual Difference?

1969 Ford Mustang Boss 429 Exterior High Resolution - image 683170

The exterior proportions of the LID Mustang are identical to the front engine of the Mustang BOSS 429. However, despite having a 429 cubic inch V-8, the LID Mustang is trimmed like Sportsroof 1 Mach. There is even a front hood, to cater to the public. Original steel wheels, eight inches wide at the front, six inches wide at the rear, reverse-offset, to maintain stock track width and then camouflaged with full wheel covers from the Lincoln dumpster.

Why Didn’t Ford Succeed?

Ford’s training in converting the Mustang BOSS 429 from a front-engine layout to a rear-mid engine yielded interesting results. Effective weight distribution inverted, from 60/40 to 40/60. However, despite reducing wheel spin, there is not much to gain, in terms of driving dynamics. Since the performance improvement was deemed insignificant, the project was cancelled.

What Happened to a Mustang LID?

Ford Almost Gave Us A BOSS 429 Mid-Engine Mustang In 1969 - image 1038986

According to problem Motor Trend Magazine from December 1970the only development prototype of the LID Mustang is destined for destroyer. For a long time, that was believed to be the case, but the website mentions an update from a “credible source who has worked at Ford”, according to which “there’s a good chance” that the car wasn’t dumped. In fact, one of these “reliable sources” claims that the car has been sent to a “fenced pen” where it sits with another discarded concept.

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