65 Barracuda .... Advice on "B" pillar weep hole

Look under the rocker. Are there slanted bumps in the pinch seam?

In 67 that is where water from the convert top drains out of. They literally let the water that gets past the top and into a trough around the opening of the top (on the quarters and Dutchman) drain into the front of the rear quarter. From there it goes to the lowest spots and drains out of the slanted bumps in the pinch seam and out of the car.

I don't think that hole you show is a factory drain.