Edelbrock heads Vs Jheads

I'll vote for the Eddies. Yes, the aluminum heads weigh less. But did you know that because of their superior heat dissipation qualities, it is possible to go up to 1.0 point higher on the compression ratio. e.g. Cast iron head, 93 octane pump gas 9.5:1 max compression ration before "pinging"; Aluminum head 83 octane pump gas 10.5:1 before "pinging".