on my 1938 21 stud flathead it was on the near side, top of the block at the back.  See attached picture, the bulkhead is on the right (you can see the washer bottle)
#5748
Ben Stevens
Keymaster

on my 1938 21 stud flathead it was on the near side, top of the block at the back.  See attached picture, the bulkhead is on the right (you can see the washer bottle)