Dodger Stadium road races? They were in the parking lot, and a lot of Vettes, Cobras, and Porsche participated

https://www.facebook.com/groups/stiffspeed

there is a very large gallery of photos in the Henry Ford Flikr page, drawn from the Dave Friedman collection held at the Benson Ford Research Center. https://www.flickr.com/photos/thehenryford/sets/72157628625088167/

https://www.flickr.com/photos/thehenryford/sets/72157628625088167/

http://www.davemacdonald.net/gallery/closeups/cobra289firstwin.htm  for a gallery from the driver of the #198 Cobra