F54Y indicates:
F = Flint, Michigan engine plant
54 = 1954
Y = RPO (regular Production Option) 313 = ???

In 1953, the valve cover would be attached with 2 nut on the top of the valve cover
In 1954, the valve cover would be attached with with four screws on the lower edge/lip of the valve cover.

Find and post the the following codes
Head casting code
Head date casting code
Block casting code
Block date casting code

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.