Need a set of HP3 Vortec Heads. These are the ported version.

If you can't find any HP3 heads you can call JimV (Valako) and he might be able to hook you up. He ported them when he was at Innovation Marine. #616...889...0928

Cut and paste the link.
http://www.offshoreonly.com/forums/general-q/72206-new-496-aluminum-heads-3.html

They are going to be a pain in the butt to find. First, I would push you toward the Raylar heads. Better all around. Second, try the iron DART heads, they are not as good as the Raylar or HP3 but they might have to work if you want iron. The problem is that once they are ported the intakes are REALLY thin. You can pull more HP with the aluminum Raylar heads and will have as much or more $$ in them by the time you are done.

If you want the real deal, one person on OSO might have a set "Crayola Crazy"
Next, Tyler Crockett made mine originally and has the CNC program to do them if you find a stock set - he might even have a set.... dunno.
Or, try Innovation Marine, I read somewhere that they still had a few HP3 engines crated.