As far as my limited understanding, any of the greases are too thick for the the parts that GM specified the use of oils.
Look at the specs in my post above that shows the 1940 specs for various parts: the post that starts "If 1939 is like 1940:"
Yes they are... That means we should use 90 W or 160 W oil in the torque tube and get it there by whatever means possible...
