I have a 3 inch slab drain in a basement bath I am finishing. The 3" pipe is cut flush with the floor. I bought a spigot connection closet flange which fits into the 3" drain and has a epdm or rubber seal. My ring on the toilet will not fit into the mouth of the flange which is less than three because it is reduced to 2-1/2" or less. Is there a flange that is spigot by 3"sch40 so that my wax ring fits. Any help would be appreciated!