Replacing a 56 year old toilet. Should have went with my gut feeling about the top of pipe being jagged and at one spot actually higher than the flange but didn't. Metal flange in wax ring contacted the high point of pipe, snap, I broke the cast iron flange.
I drilled holes in the lead and used a Fein Multimaster to cut the webs between the holes. I used the Fein and DeWalt saw to trim the pipe to the floor level(tiled).
Okay, I have a Oatey(PVC) expandable that goes on the inside of the 4" pipe and a Sioux Chief that goes on the outside. I haven't tried the Sioux Chief because I may have to enlarge to hole in the floor even larger. I'm leaning towards the Oatey which is tight and I'm in process of clean up the pipe ID.
Either way or either flange has mounting holes to attach to the floor. What floor? If a old lead chaulked flange was used the hole is so big there'll no floor there. Even the original cast iron flange didn't use screws.
I watch a This Old House video where they used the Oatley version which uses compression on the pipe OD and he didn't even mention or use the screw holes.
This Oatey PVC ID version seems to be so tight even before expanding it, screws "might" not be needed. I doubt if the old one was level either. I'm wondering how critical that is too since the wax ring will compensate for any uneveness? Is the pipe even level/square to the floor too?