I don't have seminary training, but I have to say that the infallibility of the Church comes through Blessed Peter and his successors, when they meet the criteria laid out in the Vatican Council. In other words, as you probably guessed the instant you saw my request above, I believe Ecclesial infallibility IS Papal infallibility, with the exception of the Ordinary and Universal Magisterium, which is also infallible (to be believed by Divine and Catholic faith, meaning Divinely revealed, so infallibility is clear).