When it comes to superchargers for open-track or racing Kenny always takes advantage of everything he can get from the engine before he adds boost. In many cases, a naturally aspirated Mustang GT may be just as fast as a GT500, with the right modifications. Not that he wouldn't use a blower to amp things up when needed.
Kenny always talks about Chassis, Suspension, Brakes, Wheels and Tires being the core performance platform. Focusing on those key elements can easily gain you more speed than a bolt-on blower or going too far inside the engine. However if he were to, as he has many times in the past, opt to use a supercharger, it would likely be of the centrifugal kind.