GO only has BiLevels in their fleet, so yes, it's those.
You're going to need to a be slightly more specific if you want any sort of meaningful answer. VIA's train lengths can vary from 2 cars on daily Toronto to London train via the "back route" to 30 car Canadians.
That's actually what I am wanting. So, for example, along the Corridor, what is the shortest and longest normal train? What about the same elsewhere on other routes.