I always prefer manifold.
Makes for a cooler running (idling) engine.
(And my MegaSquirt ECU wants it there )

On another car with a large(r) cam it's connected to ported, to prevent too much ignition advance fluctuations at idle.

IMO, ported is mostly more an emission thing because it helps for a more complete burn and hotter exhaust temps (at idle), although the factory used ported advance for as long as I know. Perhaps they installed it like that for a more steady/stable idle-quality.