As title says. Is it possible with a Calum RT?

Yes, you can run it on that, but you won't be very efficient. That much compression will really need higher octane to kill any chance of pre-ignition. You'd be better served to either lower the CR, or run higher octane fuel. Another option would be to convert the fuel system to E85. You could run that compression then with teh Calum RT. You'd need much larger injectors (which I assume you already have), and an E85 capable fuel pump.

Absolutely. You can tune the timing map for virtually any combination of CR and fuel octane.

Dave