Since the graphs you sent above mention an LS7 Head,
I am going to assume the intake valve size is 2.204".
I can't read the graphs, print is far to small.
I also can't save the chart so that I can enlarge it.
If you can resend the graphs as a simple 'jpeg / png', that would be better. . .
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If you want to make 1000 HP, as did
@MrSurly, then here is what you need to do.
Assuming the camshaft has an intake lobe duration of 235°, as did Surly. . . .
1000 HP / 4 equals 250 HP per cylinder.
Each HP requires about 1.5 CFM per HP.
So the cylinder heads need to flow (250 * 1.5)=375 CFM.
That flow needs to be 'all in' by convergence lift.
Convergence lift for a 2.204" valve would be (0.25 * 2.204)= 0.551 'Net Valve Lift'.
Port size / volume is associated with flow, as well as velocity.
To large a port / runner and the velocity will be to low to make good hp.
Put all the above together with an intake runner volume of
~295 cc to ~305 cc and you should be good.
If the heads won't flow as I stated above, don't make the intake
runner as large as I stated just above.
Cheers
