The last Ford I (attempted to) port match became obvious it was a wast of time. I got the felpro gasket, market it out and started on the C9 429 heads. I had an old offy intake the po had port matched to a felpro. As I realized how much material I needed to remove and looked at the intake runners I realized all I would have was a big enlarged section in the intake flow path where the head/intake intersection was.
I have no substantial proof but I always took the advice against the mirror smooth intake finish too.