Hi folks.
As the title reads, I need to find out what type of gear oil needs to be used in a 4 speed toploader gearbox.

The manual asks for a Mild E P Gear Oil, C3RZ19647-B, which doesn't really help much.
I need 4pts, which I roughly calculated to about 2 litres.

I had some 75w 85w but it has been so long since I've used it, it has nearly turned to water.

I have done a search but all answers are different.

Any help appreciated.
Thanks