are the sizes and cfm rating's on this website good

http://www.diyporting.com/flowbench.html

I need to know the cfm for these size orifices

3/4

1/2

1/8

7/8

 

It's not quite thate easy to say a 3/4" orifice has X cfm. There are to many variables left wide open. I suspect you are trying to build a flow bench, novel idea. Getting a home made flow bench to flow accurately is not that easy without all the correct instrumentation. Here is a link for some calcs related to flow.
http://fire.nist.gov/bfrlpubs/fire97/PDF/f97087.pdf

You can build a unit that will tell you if you flow has increased, but without a constant temperature, pressure and humidity, the results could be missleading.