I would go with the cast heads and have them ported and worked and use a cam that can work the head 100%.The eddy heads are good,if you have a big cube motor and 600-700 lift of cam,if not,use dthe cast units,mrmopartech
the aluminum edelbrocks are little more that aluminum versions of the cast x's or j's they are a good head dont get me wrong but you can throw them on a stock 318 with a 4bbl and it will be fine