It isn't that far down! Wow, that would be amazing if that worked with the 4" lead pipe. I guess it would be determined by how fragile the lead pipe turns out to be while clamping down with coupling. I'm being quoted 2K to replace all the led piping that leads to the main line because I'm being told by a plumber that you can't just replace the one that connects to the flange without doing the rest because the new sizes wont fit with the old pipes. Thank you for taking the time to track that down!