here's a 525 hp LS3 in a customer's car. We have put some miles on it and it is his wife's car and VERY streetable. Rough idle but the factory converter works fine. Makes crazy power. It is a circle track grind that wanted to continue making power past 7K. We didn't feel comfortable spinning it that high
We put a Victor Jr on it with the Mast throttle body adapter so we could run the cowl air cleaner.
did I mention it makes alot of power