I remember doing this before.
I used to be really smart - got A's in High School Geometry and all. USED to be anyway.
What I remember says that Muscle Chart is telling you to mill the intake TWICE what you should actually mill.
And if you do that you've ruined the intake.
Try a test fit first without milling.
Then if needed, mill HALF of what that chart says on each intake manifold face.
Then check the fit again.
I think the math on that Muscle Chart is the same math that gave us the S (S=Small) intake and the C7AE-A "TP" (Tiny Port) heads.