I don't want to cause any issues - I'm new here - It will be a very, very nice engine - but it won't make 500HP. I can pretty guarantee that - I've built and dyno'd a couple of these over the past few years. Low to middle 400s is realistic - maybe 435-450.

Edelbrock is - to be kind - rather ambitious on the advertised flow rates for the heads. They are closer to 252 cfm at .600. This is compounded by the fact that the pushrod pinch point - a significant flow restiction - in an FE is in the intake manifold