No, Ford has not announced the arrival of a larger engine for its Mustang and F-150 models. Please note, therefore, that what follows remains pure speculation. However, there is some basis for it.
That basis comes from the mouth of Jerry Dias, president of the Canadian Auto Workers Union (Unifor), who suggested that the company might be working on a new 6.8L engine and that it would be used with versions of the Mustang and the F-150 pickup truck.
Dias mentioned the possibility of a 6.8L engine at a press conference in late September, and he added the new unit would be built at the company’s Windsor, Ontario plant.
A recent press release issued by Unifor states that "Ford has committed to supplying the new 6.X-litre engines to the Windsor plant, as well as guaranteeing the assembly of the 5-litre engines and the machining of existing components at the Essex plant, as well as all derivatives."