intended use is very important. 500hp in a street car is not as fun as it sounds. 500ftlbs doesn't mean much in a race car though... Look at where you'll spend 80% of your time and design for peak average power in that area.
a street car would be about 2,000-5,000 RPM. A race car would be about 5,000-7,000 RPM. You may be somewhere in between.