This is pretty far out there, but I have seen switches for blowers. Let me explain. You have a switch in the cockpit that turns on or off the blower. This way you can have the "mild" side with the blower off, and the "performance" side with the blower on. I have actually seen cars with these, but the Ford in "Mad Max" also has one. The only problem I see with this is tuning such an engine. You must have a comprimise between a blower and naturally aspirated with both cams and carbs.