While most people were still getting their heads around the brute-force Boss 429 Mustang back in 1969, Ford’s engineers were quietly cooking up something no one saw coming – a mid-engine Mustang. Yes, you read that right.
Known internally as the LID Mustang, short for ‘Low Investment Drivetrain’, this one-off prototype took everything that defined American muscle and flipped it quite literally.
Instead of throwing the heavy 429 V8 up front like the production Boss, Ford mounted it behind the driver, over the rear wheels. Wild.
Why? Because the Boss had balance issues
The factory Boss 429 was a beast, but it came with fairly flawed 60:40 weight distribution. Heavy at the nose and light over the rear tyres, it was unsurprisingly prone to wheelspin.
Ford wanted to see what might happen if they reversed that, so its engineers teamed up with their Special Vehicles crew and Kar Kraft, the legendary Detroit skunkworks outfit, to pull off one of the craziest Mustang experiments of the era.
They engineered a removable rear subframe, mounted the Boss 429 and a C6 automatic transmission in the back, and used a custom-built transfer case to flip the power 180 degrees. It all drove through a beefed-up Ford 9-inch differential.
The result was a Mustang with a 40:60 rear-weight bias, and potentially the best-handling example of its time.
A nod to the GT40
It’s no coincidence this happened right after Ford’s GT40 program had just dominated Le Mans. A mid-engine layout was the hot ticket, and Ford had seen first-hand how that layout could revolutionise performance. The LID Mustang borrowed from that philosophy—a raw mix of muscle car and race car logic.
So, why didn’t it happen?
Despite all the engineering trickery, the car didn’t deliver a massive performance boost. Sure, it gripped better and handled with more balance, but it wasn’t enough to justify a mid-engine Mustang production run.
The prototype was parked, and the idea faded into the shadows. Then, it vanished altogether.
Some reports claimed it was crushed at a Detroit salvage yard, but recent whispers from Ford insiders say otherwise. Supposedly, the LID survived and may still be tucked away in a private garage near Dearborn or Allen Park.
If true, it could be one of the rarest and most mysterious Mustangs ever built.
Why it matters to us
At Retro Rides, we live for these kinds of stories – the ‘what if?’ machines, the bold experiments, the prototypes that nearly changed the game.
The LID Mustang wasn’t just a test mule – it was a glimpse at what muscle cars could’ve been had Ford followed the GT40’s path not just for the track, but for the street as well.
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