LarrBeard may be referenced in a movie about it. I think he was played by George Clooney. Something about staring at goats.
That is a GL4 SAE rating. GL4 is considerably thinner even though the weight number is the same. GL4 is rated differently then GL5 or traditional gear lube that you put in an axle. Here is a good conversation about "weight vs pour-ability".
https://willysjeepforum.kaiserwillys...ox-Lubrication