If it is open ended, it is a road draft tube.

If it had been part of a PCV-type factory set-up there would be no open tube (no road-draft tube). The PCV system was introduced in 1948 delivery vans because the road-draft tube was of no use in these start-stop/low-speed vehicles.

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.