The last Ford Mustang Shelby GT500 came in fifth-generation guise (live rear axle) and produced 662 hp using a 5.8-liter supercharged V-8 engine. It was a beast of a car -- and almost undriveable in anything less than perfect weather.
The next one, based on the spectacular GT350, should be a little more driveable with the independent rear suspension setup and at least five years of extra software development. But today, we're talking rumors.
Now it turns out the next GT500, expected as a 2020 model, could get a dual-clutch transmission. That would be a first for the Mustang. We don't know if it would be a 10-speed, an eight-speed or something else not in Ford's warehouse quite yet. A supercharged 5.2-liter flat-plane crank V-8 would be an obvious guess for power, but some of our moles speculate that it could also be a new 7.0-liter naturally aspirated V-8 pumping out north of 700 hp.
You can also expect a bunch of new carbon bits inside and out, new wheels (possibly also in carbon fiber like the GT350), and a super aggressive front end as we can see in the teaser shot from Ford's future product demo a few months ago. We should get a look at the car this year or early next.
When contacted, Ford gave the usual, "We cannot comment on future product." We can, and it's going to be awesome.