Gee Dave, I would have a tough time estimating such....i read the magazine reports of 600 hp.....and the stock GM supercharged package is pretty stout and driveable. For my car, there isnt enough tire to think about more horsepower...
These engines are cool but I still strongly suggest a competent tuner to finish it off....they are sensitive to turbulence in the intake tract (as are all engines). We tried three different MAFs, honeycomb, baffles, etc. but the final result was about 20 hours of a tuning guru's expertise. I didnt believe at first what an expert could do but he made a believer out of me.

mike