Cam selection help

The way carb selection was taught to me was to multiply the displacement (CID) by the anticipated RPM is likley to turn to. It is important to be realistic when making the RPM estimation. Start by estimating peak power and add 500 for over-speed.so
CID x RPM = ? then divide by 2

that tells you how much air per minute your car uses at peak performance

then to turn that into cubic feet divide by 1728

so a 440 bored 30 over =448
448x7000=3136000 /2=1568000 /1728= 907.407 cfm
is this correct?

so the cam that peaks at 6500 add 200 and that puts me at a little over an 850 cfm