[blucar]

One of the rules I try to follow is; solve problems, don't create them. That said, trying to purchase a used 84 year old rear end in lieu of new components that are installed by a good mechanic does not make much sense.
I second Kobe's comment about a Columbia OD.. My '36 has a Columbia under it, has had since it was new. The gear ratio is 3.78 with about 25% OD. The car is very smooth running with good fuel mileage.
If you consider a Columbia you are not stuck with the mechanical shifting '36-40 unit's, the later model '46-48 units, electric over vacuum, will go right into a '36 with no modifications, using the right combination of parts. I converted the Columbia under my '36 to a '47-48 unit in 1955.