I thought this youtube clip is interesting so doing some research on it.
It’s not much and poor quality but still very cool clip of the 1965 ARRC race at Daytona Speedway (now known as the SCCA Runoffs).
Someone commented it looks like the JFK Zapruder film.
There were 16 cars in the B/P race (ran together with A/P)
10 Shelby GT350s, 3 Sunbeam Tigers, 2 Jags, and one Corvette (Don Yenko's 1957 Fuelie)
The 1963-65 Sting Ray and the AC Cobra ran in A/P in same race.
Don Yenko finished 3rd in B/P with failing brakes (amazing run)
Mark Donahue, in the dark color GT 350 qualified 2nd overall. (Mark had an amazing qualifing run)
Jerry Titus won the B/P race in a GT350
https://www.youtube.com/watch?v=AsL_W7I5OlA