Diff oil question

[partsman]

So, I have access now to Schaeffer diff oil #209 moly universal gear lube SAE 90 and also Esso Gear Oil GX 80W-90
is one superior to the other?
I am thinking of using one of them in my Diff on a 1977 F-250 Super Cab 2 wheel drive, that I use to pull a 18.5' fifth wheel.
I imagine they should meet the specs.
Anybody know?
Bill

 

[dailydriver]

I've heard MANY good things about the Shaeffers 209 on my car forums. If I did not have to buy bulk/big order, I would probably use it in the 10 bolt. I have not heard anything about the Exxon stuff though.

 

[partsman]

Thanks for the reply.