Sorry, can’t offer any solid info on this. My ‘37 came from the PO without the wiper and I opted to install a single electric wiper motor. I agree with the observations Harold and Tiny offered. I will offer FWIW, that the plumbing connection at the manifold is different for earlier versions of the 216 I have and have seen than the one shown in the above photos. The manifold port is on top and aft of the pipe center.
