3835913 head was 1954 and 1955-1st
What is the date casting code?

I'll look up info on the late 55 head (hp also increased).

112hp in 54; 123 hp in 1955-2nd

rocker arms changed

The block was significantly different with respect to the water pump have internal vanes in late 55.

Maybe Pre '68 Dave will have information about changes?

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.