1950 it is

1949 3116 - end gates (no Suburban models with rear doors on 1947-1949 Advance-Design Chevrolet (and New Design GMC) GM trucks

1950 3106 & 3116 - rear doors & end gates - no vent windows on Advance-Design (and New Design GMC) GM trucks (as shown in the photo)

1951 3106 & 3116 - rear doors & end gates - vent windows on 1951-55 Advance-Design Chevrolet (and New Design GMC) GM trucks

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.