Side Marker location

I was out in my shop tonight and measured my side marker lights. There is a body line that runs from front to back on a 68. That goes through the center of both front and back markers. Measure 5 3/4 inches from the front of the fender along the body line and you have the middle of the front marker. Measure 4 1/2 inches from the back of your quarter panel along the body line and you now have the center of the rear marker light. Hope this helps you out! Good luck and let me know if I can be of any more help.