Well with the smaller cam it made more max power? And its torque peaked earlier. I'm pretty satisfied with the ole .572/.590 but it may be worth the swap to the smaller cam, as I've been running this one pretty hard for the last 6 years or so.
And as for the heads I know they were disassembled bare heads when I purchased them from a friend for 100 bucks, and had my local machinist port the hell out of them. Who says you can't make big power with camel humps... I think 500+ horse and 470+ torque is pretty good.