I don't see any denail here....
Being that it is the official Pontiac website... name names, people, give some spec.*, etc. etc.
Performance people don't keep thing under-wraps. Furthermore, you'll notice that the salt flats Bonneville wasn't intercooled. That'* the trickwith using Roots and Screw type blowers is that using an IC isn't productive, unless you use a Water cooled IC to cool the air below ambient temperatures.
Since they "Suck" air into the engine instead of "Blowing" into the engine.
Furthermore, if you read about the car, you'll see that the Twin-screw that was used wasn't a peice that was recommended by Kenne-Bell. It was picked out and modified for use by a performance shop. So no, Kenne-Bell won't have it in their applications list. They're not trying to bullshit you, they just weren't responsible for it.