Unless you have a chamber to accept clay pipework, (and that will also depend on the O.D. of the clayware, it has changed slightly over the years with new ranges of pipes), you'll have to use some sort of adaptor to get from clay to plastic, and then use a couple of plastic stubs on the chamber which will act as rockers. Can you get an ID off the coupling just visible in the picture?
Alternatively, if you can remove that coupling just visible in the picture then swap that for a clay to plastic, you could go from there in plastic, then back to clay the other side of the chamber. maybe better as you avoid cutting the clayware, but may have to be whatever is easiest.