That was about 5,300 and he was adjusting trim/tabs. The driver was almost certainly Bryan Forehand who is Reggies right hand man and test driver of most all the Fountains. The throttles were probably mashed forward while the drives were set conservatively......(around 75 mph). As he adjusts drives/tabs the rpm's start coming up as drag is reduced eventually building speed to about 102 at 5,300.
I'm curious about the drive/tab setting indicators too. I never had that type and it appears the drive numbers run backwards. I'm also curious what motors were in that 42. 700's would be faster than that and I don't thing 525's can hit 100.....and the 600's are not a very popular motor but the HP to MPH numbers suggest that was what was in it.