Budget D100 360 Suggestions

If you go with a larger cam (most of the ones suggested) the 600 will limit the top end. But with a smaller cam, and with your dad just 'putting around', 600 cfm would be fine IMHO. I've run a 350 ft-lb torque engine that would still wind out to 6500 RPM on 600 cfm. (The old Holley 6619 mileage carb.) That small keeps it easier to tune too.