Engine Quest Dodge Magnum Heads New Zealand castings.

I just scored a pare of Dodge Magnum EQ heads New Zealand castings at a local swap meet here in AZ. the bowls are cut for a 1.62" exhaust valve and a 2.02 intake valve. They are brand new bare assemblies still in the boxes and were stapled shut. They have a website on the box but I can't get to the original website, since I guess they are no longer in business. www.toowoombaproducts.com Can anyone verify the intake runner cc's and what they might flow. Do you think they can support around 500HP. They are going on a 1996 magnum 360 that maybe stroked to a 408.