Reference: Manual Transmission Oil

[Wayne Hingley]

Originally Posted by Alex van de Wetering

EP doesn't necessarily mean it's not compatible with yellow metals!

You are correct Alex. There are several specialty oils with EP additive packs that are yellow metal "friendly".

Les: I have decided to use Royal Purple MaxGear 75w90. It is available through Canadian Tire.

Below is some info from their website:
Max Gear is recommended for use in truck and automotive front or rear differentials, manual transmissions and lower gear units of marine engines that specify use of an API GL-5 or GL-4 fluid. It is non-corrosive to soft yellow metals (brass, bronze, copper, etc.) and synchronizer safe.