Ford built the 2011 Mustang GT 5.0, and it was good. Then Shelby built the 2011 Shelby GT500, and it was great. Mustang squared, if you will. But as often happens, another tuner takes the twice worked-over GT500 and applies some additional tuning and tweaking (and sometimes a complete overhaul). Does that make it Mustang cubed?

Well whatever you want to call it, Hennessey Performance took the already-awesome Shelby GT500 and injected it with some poison all their own. They call it the GT500 Venom 600R package, and it certainly lives up to its name.

More of an upgrade than an overhaul, the Venom 600R package adds a number of small enhancements over the Shelby production car that end up adding a lot of power. The supercharger pulley was upgraded and a high flow induction system was added. A mass air sensor re-calibrator was added alongside an engine management calibration from Hennessey. Dyno tuning, professional installation and a one year/12,000 mile warranty are also included.

So what do these upgrades net you? Well Hennessey says its good for 605 horsepower and 590 ft-lbs of torque at the flywheel. But how does that translate to the dyno? Well this video shows the GT500 Venom 600R making 525 horsepower and 502 ft-lbs of torque at the wheels. Figuring a 15% drivetrain loss, it looks like Hennessey is right on the money, as usual.