Not that I disagree with you but the company website disagrees. They state "in excess of 1000HP" concerning the 366" engine they sell. They even have a graph showing over 1100hp. It is worth noting that that state 100 octane fuel and an intercooler was needed to make that much power. With their reputation at stake I don't think they'd make false claims and place false ads.
With that said, I agree that it's easier with larger turbos, more boost, less compression and a big intercooler. However, I don't care how easy a turbo is on the rotating assembly, a stock 1st generation block will not handle that much pressure long enough to enjoy it. I doubt it'd last long enough to tune it for that much power.
We're talking about rear wheel horsepower right?
1200-1400hp at the flywheel would get you over 1000 at the wheels. It's a very different ball game when it's in the car. Yes, I agree the Banks kit won't touch that.