Ford Repair: HP gaining, twin screw, aspirated engine

Question
How much HP will the 4.6L 2 valve gain fully modified as an Naturally aspirated engine?
(no boost of any kind)
I'm mean computer to stage 3,heads (Pi high compression heads) large cams, large intake, and full length headers. All the good stuff.
Without getting bored out or anything.

I was thinking it should be about 550Hp with all that

Answer
Kevin-

  Honestly, without a power adder the 4.6L 2 valve motors won't make as much power as you'd think.  The most I've ever seen one put down in naturally aspirated street-driven trim is around 450hp.  That's certainly not bad, but it would take about half as much money to make that with a naturally aspirated pushrod motor.  And it's not nearly what you could make with a good twin screw blower or a turbo.  Hope this helps.

Steve