If I were inclined to set up a PCV setup on my 235 (which I am not), I would sooner get my hands on an early 216 downdraft tube which came with an oil fill cap on top of it, and put the breather cap there, plug the bottom of the draft tube, and put the PCV valve on the top of valve cover. The hose from the PCV valve can be plumbed to the wiper fitting with a T fitting.
There are a lot of nasty watery vapors which like to collect on the underside of the valve cover. A PCV valve located on the top of the valve cover would sip that away quite nicely.
