Stock works just fine and there isn't anyone on the board who has enough N/A power to justify changing it.
The money you would spend on an I/M would be better used towards cams, expensive as they are.
Or if you want more RPM, oil pump gear and valve springs.
For reference,
I have a SVT head with a Ford Racing Intake Manifold. The first gen manifold almost fits perfectly. Runners are about 1/16" off but can be ported to match. Also the alternator bracket needs to be slotted so the alternator moves down about 1/4".
And good luck finding one.