An elusive Ford Mustang Boss 429 packing an enormous 7.0-liter V8 under the hood has cropped up on Mecum recently, sporting a fully restored exterior and powertrain. It ultimately went for a cool $297,000 despite not being a restomod (or, perhaps, thanks to it).
The Boss 429 Mustang series emerged in the late 1960s as a homologation batch for a NASCAR racer. Ford never put an engine as large as that into a Mustang, so it ended up contracting Kar-Kraft to do the re-engineering. The tuning company devised a new subframe with engine supports, reconfigured the suspension and moved the battery into the trunk. Even with these modifications done, the Mustang was considered an extremely dangerous ride for amateur drivers due to unresponsive handling and poor cornering (see video). It traded those for exceptional straight-line performance, though, and was rather desirable back in its era.
The engine shipped with a manufacturer-rated 380 PS (375 hp / 279 kW) at the crank, but unofficial reports claimed it was actually capable of 507 PS (500 hp / 373 kW) or so. The torque also came close to 600 Nm (441 lb-ft). The transmission was four-speed manual, and the drive stayed on the rear axle.
Although Ford ended up making 1,358 such cars, it is understood that not many are still around 57 years later. This example has a certificate of powertrain authenticity from Ford and comes with a fully documented restoration that saw its exterior, cabin and drivetrain rebuilt. The odometer shows around 66,000 km (41,000 miles) of use, but the listing claims it has only been driven for 150 km (93 miles) or so post-restoration.
