Ford has reportedly confirmed that its new 7.3-liter V8 could be fit into a Mustang or half-ton F-150, but that the engine will at no point be an option from the factory.
This 7.3-liter V8, an optional engine for the updated F-series Super Duty, will have a cast-iron block and a forged steel crankshaft. Valves will be actuated by an in-block camshaft complete with variable valve timing. Horsepower and torque figures have not been disclosed, though Ford claims that "this 7.3-liter is expected to be the most powerful gas V8 in its class." Expect greater power than the Super Duty's base 6.2-liter V8, which makes 385 horsepower and 430 pound-feet of torque.
The automaker's North American product communications lead Mike Levine confirmed the 7.3's compatibility with both the Mustang and the F-150 to Motor Authority, whom he also told in no uncertain terms that the engine would not be suitable for the Mustang. Despite its high displacement and suitable dimensions, Levine reportedly pointed to the 7.3's cast-iron block as too heavy for use in the relatively light pony car, be it due to front suspension constraints or weight distribution issues.
Levine reportedly expressed certainty that the 7.3 will eventually find its way into a Mustang, though only as an aftermarket project, and not a Ford product.
Mustangs have historically had engines nearing the 7.3's displacement, with various 7.0-liter engines available between the 1967 and 1971 model years. Since 1971, no Mustang has left the factory with an engine larger than 5.8 liters, and even the upcoming 2020 Mustang Shelby GT500 will use no more than 5.2 liters to make its 700-plus horsepower. With internal combustion engines only getting smaller with the march of time, the days of throwing more displacement at a problem are gone, along with 7.0-liter Mustangs (or bigger, with supercharger volume included).