My recently purchased 1930 Hudson calls for straight 140 Gear oil for the differential.  I can't seem to find that stuff anywhere in Canada.  Not available in Canada through Amazon.  So I may have to use 85/140. I'm curious on any thoughts about that compromise?   I'm not sure if the temperature specs refer to ambient or differential internal temperature.  I'm on the west coast of BC so the temperatures are pretty moderate.  I plan on using the car as a 365/daily driver not nothing more tha