Does your car have screw holes in the rocker panels?
Pull the clips out so we can see them, and can tell you top from bottom.
The clips retain the top edge of the rocker trim. The bottom edge of the rocker trim is held on by screws the go in up from underneath the rocker.
Not all cars had the front retaining screw. Seems 66 cars didn’t have it. But I have a 705 SPD 1967 Car that doesn’t have the front screws either. Car has been repainted and the rocker trim was taped off not removed.I would add that there is a long chrome screw that goes in the leading edge at the top and screws into the body
My factory trim had the holes the reproduction did not
I had to add them.
You could probably go with out them but they do add a bit of safety by pulling the leading edge into the body closer