Carburetor cfm for a mild 318 build

I'm a Holley fan, but a 600 mechanical secondary carb would be my choice.

Don't get caught up in the whole advertised power band. It's all BS. My cam is advertised something like 4500-8500RPM powerband and makes peak power at 5,900rpm and dyno pulls down to 2500 still show big numbers down low.