rocker arm casting codes

1953 is an "odd ball" transition year.

In 1953, the 235 Powerglide-equipped car engine was a high-pressure engine; but,
the 1953 truck engine and the 1953 non-Powerglide car engine were low pressure engines.

They had different heads and different numbers of head bolts (how many head bolts on your engine?).

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.