There was another dash cam video with rpm/mph/gear/g force.... From inside a 69z. The shifting was going on above 8,000 rpm much of the time. That driver did not seem to be as smooth through the corners as the mustang driver.
Shoulda linked it! Gonna go look for it now lol
EDIT: Found one with a 67 Z28. OMG that guy winds that poor motor out so hard