From the Shop Manuals:

1949 and earlier 1/2 ton (Huck style brakes): After tightening to a slight drag, back off 5 clicks.

1951 and later 1/2 ton (Bendix style brakes): After tightening shoes to a slight drag, back off 14 clicks/notches.

http://chevy.oldcarmanualproject.com/shop/1948_51truck/51ctsm0513.htm

By 1954, the advice on 1/2 ton Bendix brakes was back off no more than 7 notches.

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.