I will agree that the fan noise is excessive on a car from 1937-1940 that came from the factory with a 3.73 axle ratio.
I used to install one of those fans on my '39 for prades to keep the temperature down and the fan noise above 40 MPH made it sound as if you were in 2nd gear.
If often drove the '39 with 4.22 gears from 60 to 65 MPH and after I installed the 3.73 gears 65 to 70.