Which head/combustion chamber is better for performance? Speed master aluminum LA or aftermarket magnum iron head?

Edelbrock Aluminum Magnum and:
Mopar did an Iron ‘R/T’ head
Maybe the Engine quest head (from ?Auatralia??) was also better than the Chinese magnum repo head as far as I remember from the forums-something about a water jacket plug on the side of the good heads..??
I meant available new.