It's not a GP race, though. This is from the Laguna round of the AMA Formula 1 series. It was before Superbike was the premier AMA class. At Laguna the main event was the "twin 100k" races with Formula 1 equipment - TZ750's were predominant, but GP 500's were eligible. Kenny Roberts won this event, and it was supposed to be his last ever race. Then he decided to give it one more try in '85. I was there in '84 for the event pictured - the first national race I ever saw in person, and with one exception, I've gone to Laguna every year since. Which one did I miss? The '85 race, of course! That one really
did turn out to be KR's last stand...