Building a 410 stroker and need some advice

Also remember people that gas has a higher rating of octane than
petrol....

So i think 11.1 comp will be more than fine.

My mechanics 360 has iron heads an runs 11.3.1 fine on pump fuel.
Remember were in aus haha.

When it comes to octane ratings between the United States and down under, what's the differences? How does our 93 octane stack up next to yours or what is the equal?