That is frikkin awesome!
Edelbrocks do require a good amount of porting, but like Rusty said, the LaRoys are very well known engine builders and could probably help you out if that's your quest.
W5s are capable heads, but of course require special pieces to make them work. (rockers, intake, exhaust). Then again, if you want 600, that really means you're hunting for 700, at which point in time, you may want better heads than Edelbrocks anyway ;)
Regardless, if you want 600, you'll be dropping some serious coin on top end parts...so don't skimp unless you want to be disappointed.
