EQ Iron Ram vs Edelbrock Performer

The Eddy Magnum heads are advertised at 58cc combustion chambers, but they are more like 62 to 63cc, I had to have mine shaved .030 to get to 58cc
Out of the box the valve stem clearance is too tight and must be checked.
Aluminum heads allow you to run higher compression as a lot of the heat is quickly absorbed into the head, heat in the combustion chamber makes power, hence getting the combustion chambers ceramic coated.

Don't get me wrong, love my Eddies and would take them over iron heads any day, but I have lot of coin them.