[Coupeguy2001]

The front "marker lights" are the parking lights, but they were used for events like going to a drive in theater, and not disturbing the moviegoers with your headlights on.
In 1963, it was determined that the turn signals could double as "marker lights, and the parking lights were turned on with the headlights.

If you want this for your early truck, there is a spare terminal on the headlight switch for the tail lights. Since that same switch was used for big trucks' marker lights.
Just move the parking light wire to the aux tail light terminal, and they will be on whenever the tail lights are powered, IE, anytime the headlight switch is on in any position.