Thanks for clearing this up, fourth year. The lead drain for the toilet is horizontal, going into the hub, whose face is vertical. The hub is a tee off the main stack. I wondered how a vertical connection could be easier than a horizontal one. I guess I had my terms backwards. Does anyone want to change their answer? Sounds like you’re telling me not to cut the hub off. Maybe this quick attempt at a diagram will help.
h u b | t o i l e t f l
As a side note, if I want to get rid of the cast iron altogether and replace it with plastic (sorry Sylvan!), what are the chances the cast iron is supported inside the wall of my one-story house? It can’t be as easy as cutting it loose in the attic at the top of the wall and having it fall to the floor in the basement. Can it?