Yeah, Fordahl has one he is close to finished with with a GT3 cup engine in it. They are very close to the engine being done and now just need to do the lightening. As it is, a mostly stock Boxster is insane.
While I'm sure it will be crazy fast I dont think big power is suited for the car. Boxsters have always been about balance. I dont know that you buy a lot with huge power. I'm sure with the money they have invested in the car however that it will be a winner!
I would rather have solid 300 HP in a 2000 lb Boxster than 450 HP in a 2500 lb Boxster.
Keeping the car lightweight and moderately powered means less chance of mechanical failures as well.
Knowing it is one of Greg's projects I am sure it will be a winner no matter what they do. He tends to have a magic touch. That and he knows more about race cars than I ever will.