The lower unit was also used on models as early as 1934. The model 4016, for example, which is a 4 HP motor with underwater exhaust.
It may also be the same lower unit as used on the 1932-33 motors like the Sportwin or Elto Fisherman, as well as some of the brass lower unit single cylinder motors. The difference would have been in the size of the anti-cavitation plate. 1932-33 motors had a very small one, the 34’s were larger. The anti-cavitation plate was part of the water pump, as you can see in your photo. I’m attaching a picture of my 1932 Evinrude Sportwin for reference. Hope this helps.
Best,
PM T2
He's livin' in his own private Idaho..... I hope to go out quietly in my sleep, like my grand-dad did..... and not screaming, like the passengers in his car...
