The cylinder head material only plays a small part in figuring how high a compression ratio you can run because the chamber temperature should be slightly higher than aluminum. The chamber design, quench, intake air temperature, and the engine (chamber) temperature need to be considered. Along with dynamic compression pressure which is a combination of static compression, valve timing, and air pressure (altitude.)
The engine application also plays a role, because if the engine is under high loads for extended time the chamber temperature will increase (the spark plugs will also run hotter), and the engine and air intake temperatures may increase depending on how good the cooling system is and if the intake air is picking up under hood air temp of if it has a cold air intake system.

I have not tried to push the compression limits on the iron head engines because they are daily driver stuff that usually get whatever pump swill is avaliable.

The 360 that I built for my Ramcharger used KB#232 quench dome pistons, and shaved iron heads to get 0.040" quench, and I ran a small 260 duration RV type cam, My static compression was 9.6:1 and the Dynamic compression was around 7.78:1 which is about 158 psi cranking cylinder pressure. It ran fine on pump junk fuel.