Doyle,

Your heater looks like the reciculating heater in this 1954 GMC document.

The 1954 GMC recirculating heater has a different defroster-flap handle and decal/plate than yours (I have one that I think is original - the plate was missing, I think).

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.