Read this article if you haven't already:
Dyno Tested: We Make 700 HP With Trick Flow’s New FE Heads - Hot Rod Network
I know it is a Ford but it is 482 inches with a Comp 292R cam and a FAST system. This combo ran super well on the dyno but we don't have it in the car yet. I think it will run okay in the car but I'm pretty sure it will take some EFI tuning to get there.