Recommended gear oil '71 4WD Blazer

[Joe Blaze]

I wanted to check the fluids before the winter on my '71 Blazer 4WD with auto trans. Can anyone advise what are the modern day equivalents of the recommended front and rear end gear oil, and the transfer case fluid? I would be topping off, not changing out fluid completely.

Thanks

 

[big pappa b]

An 80w90 gear oil is fine