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

TT5.9mag said
Which head is that? Most of the crate engines I’m aware of used either;

Cast iron magnum head
Cast iron magnum R/T head
Aluminum edlebrock magnum head

He’s told me probably 4 times and all I know is it was a better magnum head that was on factory crate engines and is no longer available. The short side excited my fingers. Kinda like a W2 only different.