New toilet flange on old plumbing
I have a 1960s era home with cast iron waste and vents. One of my toilets has a pretty severe rock to it (slightly uneven tile work and lost tension in the flange bolts holding things down). I want to fix it as I'm going to be selling the house soon and am pretty sure an inspector will catch the "master bath toilet rocks when you sit on it". At the same time, I don't want to rip apart the entire stack for a house I'm about to sell.
The flange bolts are rusted out, so I need to at least replace them, and I'm thinking the flange is original too, so it MAY be in bad shape. I'm wary of opening up the system for fear of what else I might disturb. Worst case (and assuming the pipes are still intact), is it possible to use a new toilet flange designed to fit into a PVC closet bend with an older 3"/4" iron pipe? Assuming it is, that will likely be the easiest way to make sure things fit and work correctly for the sale.