I have read that the "grease"-fitting near the top of an SM420 torque-tube housing was used at the factory to shoot in transmission lubricant to make sure enough fluid was in the u-joint housing. This could be a myth.

Tim
1954Advance-Design.com
1954 3106 Carryall Suburban
1954 3104 5-window pickup w/Hydra-Matic
The 216 and early 235 engines are not "splash oilers" -- this is a splash oiler.