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

pittsburghracer said
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.

Were those actually magnum heads? I had two sets of those with the improved exhaust port but I didn’t think they were magnums.