This is what happens when Ford builds the epic flat-plane Voodoo V8 and decides to slap a supercharger on it.
It's been with increasing regularity that the numbers squeezed into a vehicle's name indicate nothing about the car's engine size or horsepower output. Instead, it's a tactic automakers use to cook up nostalgia and help delineate what car is being succeeded. Mercedes used to bestow the 63 name to the end of its AMG models using a 6.3-liter engine, but now it most of its AMGs use a 4.0-liter V8 with no name change. Ford does the same thing, with the Mustang GT350 name having no association with the 526 horsepower it makes.
It's power output even encroaches on the fifth generation GT500's 550 ponies, but thankfully we're in the midst of the muscle car era all over again and too much power is never enough. With the 707 horsepower Dodge Challenger Hellcat stomping around and what's likely to be its more powerful replacement looming around the corner, Ford cannot afford slack. Especially not when Chevrolet has just added the 1LE handling package to its 650 horsepower ZL1. Assuming that Ford is still in it to win it, Car and Driver speculates that we'll see another super 'Stang by 2018, when it's predicted that a new version of the GT500 will be out and thirsty for Hellcat blood and Camaro bone marrow.
Given the recent switch to an independent rear, this will be the first GT500 with a IRS. Additional track control will be added by widening the Mustang's track, playing with aerodynamic bits and bobs, and adding wider tires like Dodge will do with the Challenger SRT Demon. Enhanced cooling will be standard as well, with a larger grille and upsized lower intake added to the many vents and slots the violated sheet metal will have. However extravagant that may make the GT500 look, the hardware is needed because Ford might be going with a supercharged version of the 5.2-liter Voodoo V8 from the GT350 with its flat-plane crank traded for a conventional cross-plane setup to power this Shelby.
Direct fuel injection will be added, especially because that engine will have use every strategy possible to outdo the 662 horsepower supercharged 5.8-liter V8 that Ford used in the previous GT500. Expect a reveal later this year along with a few leaks prior to that if any knowing Ford employees come clean (hint hint).