Lucas Bell 
The Ford Mustang and V8 engines have gone together since the early days of the muscle car era. It may be true that engines with less cylinders have powered the pony car in the years since, but the high-performance models have always had eight-cylinders under the hood. Had things gone a little differently in Dearborn back in the early 2000s however, that wouldn’t be true. At one time, Ford was playing with the idea of building a V10-powered Mustang.
While the idea of a V10-powered Ford Mustang sounds ludicrous today, things were a bit different a few decades ago. The company had just rolled out their new line of modular engines, which included the Triton V10. With truck customers needing more power than what the new 5.4L and 4.6L V8 engines could offer, FoMoCo made the 6.8L V10 by sticking two more cylinders onto the larger V8. A simple solution, but one that got Ford’s Powertrain Research and Advanced Engine Development group thinking.
The team would go on to create another V10 engine, this time based on the more compact 4.6L V8. It measured a familiar 351 cubic inches, and featured quad camshafts borrowed from the Corba R’s V8. Crucially though, this V10 featured an all-aluminum construction. Ford had to run the motor with two computers that each thought they were running an inline-5, because their cam setup ensured their existing V10 computer wouldn’t fly. According to Autoweek, the engine produced 426 horsepower and 400 ft-lb of torque when powering the 1999 Ford Mustang prototype known as the Boss 351.
The Boss 351 is one of the coolest Mustangs on the planet. Beyond the V10, it features a tried-and-true Tremec T56 six-speed manual gearbox, a Ford 9-inch rear, upgraded suspension and brakes, and a few stylish tweaks. It’s fast too, as it’s able to dispatch the 1/4 mile in under 12 seconds. But alas the global circumstances of the early 2000s proved too much for a super-expensive V10 powertrain to overcome. The idea of a V10 Mustang ended there, as did the engine’s future role as the heart of the then-still-secret Ford GT.
Even as the future of the automotive market seems to be rife with overly wound-up small displacement engines and batteries for propulsion, Ford may be keeping the high-octane flame alive with a rumored 6.8L V8 engine bound for both the Mustang, as well as the F-150.
