Ported intake gain?

Take your time and do a nice gasket match and blend into the manifold 2 inches. Radius the top of the plenum and run it. Do a neat job and you probably gained 80% of what a well ported manifold gets you.
This ^^^ or call Wilson manifolds and offer up one arm and two legs. Their porting is expensive but from all who’ve done it say it’s worth it.

Wilson Manifolds