Originally Posted by Whitelightning
Isn't there a reinforcement plate on the driver's side under where the antenna goes? Or is that for the outside mirror.

No plate (that I remember) - original style antenna.

http://chevy.oldcarmanualproject.com/radios/51rs/51rs40.htm

There is a mounting bracket near the bottom of the original-style antenna that attaches to lower inside cowl (in some/all A-D years there might already be a hole for the attachment screw).

Non-original design antennas might or might-not have a lower brace/bracket.

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.