Steve:
I would agree that normally the package I have would be about 30 hp short of the 600 mark but my heads were sent back east to Kenny Bernstein's shop where they did some welding, machining and port work. Apparently they flowed 20% more air when they came back.
Who knows, it might not have made 500.....
Bad Penny has been an inspiration for me throughout my build.
Thanks for the compliment.