Alloy heads

Ahhhhh, no.


It’s a bit more complicated than that but in the end, aluminum is better.
It is a combo dependent thing on how far you can take anything.
All things being equal, I’d run iron up to a 10.5-1 & pump gas on a good street cam.
With Aluminum, I already at 11-1 and a smallish cam. 224@050 & 93 octane.
Compression is compression. Air fuel explosion is air fuel explosion.
The amount of energy released is the same on a otherwise everything equal engine. Efficient and effective beast removal from the head will allow more compression.