This of Smokey Yunick. Taken at Pocono race track in early seventies. USAC was the sanctioning body. Smokey was a very crafty racer. His car was powered by a stock small block engine (Chevy) with mods allowed by USAC. Enlarge to read the logo on his back. He was an interesting person and one of the many I studied when I was younger. Want to read more. Search Wikipedia. Sorry I can’t get link to paste & copy on this lovely iPhone.