Its billed as a barn find, but there isnt a speck of dust or a single flaw to be found on this 1967 Mustang fastback nicknamed Helleanor, a claim skeptical viewers might want to take with a grain of salt. Underneath sits a 402 cubic inch small-block pushed by twin turbochargers to a claimed 3,000-plus horsepower, running low-4-second eighth-mile passes while reportedly holding back another 1,500 horsepower in reserve. Between the staging precision and that unmistakable turbo whistle, its easy to see why this ones racked up over 1.6 million views. Just how much is this car really capable of?