There are so many varables involved and routes to take. That setup with supporting components (TB, Exaust, ect) would net a good 350-380RWHP and still be street freindly.
Ninjacoupe on here has that combo with an FTI cam. He made 386hp. He told me his cam is built for torque and not all high end power. He makes his power under 6000 rpm. So what i'm getting at is if you spin it a little higher, you'll easily hit over 400hp. I say spin it to 7000, use a victor 5.0 intake and enjoy 430rwhp and still have plenty of torque down low.
My friend has a 347 w/ the edlebrock heads and the e303 cam, w/ a cobra upper and lower - and that thing is much more than a beast, its un real... i wonder ho wmany horse it has, never been on a dyno