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

dusterdoug said
My 2 cents…

I built a 416 years ago that went 10.14@130 through the muffs…with a flat tappet cam…and EQ heads.

The same guy that did the EQ heads for me has Speedmaster’s on his Dart: Tickling 300 cfm after some lovin and rubbin.
Click to expand...
That's impressive. Did somebody in california do the heads?