didn't Andy do an A&A (allegedly better then the OEM Maxie intake) on his 514 with more compression, Indy EZ's and a larger cam and it made I think 640-ish?

I think you can make 600 lb/ft+ with the right streetable cam but the 600-ish HP might still be a stretch with the low CR and (lower) hydraulic lift cam.

The Hughes cams seem to have among the best rate of lift for duration hydraulics out there, it will help because the Stage III heads tend to stall at low lifts so to make power you typically have to old school "hang em and squeeze it" (long duration & high compression to hang on to the torque well past peak to get the RPM)