Just found 2 possible candidates for the rear differential oil that would appear to meet the required specifications...
1- Mobil 600 XP Series (EP) mineral based oil suitable for spur, helical and beveled gears available in 90 W # 103542 and 140 W #103495. Lastly should I go with the 140 W if I am in a hot climate even though I will not be working the truck hard?
