Wouldn't it be easier to time the big end since everyone is watching the starting line....It would be easy to hide a small relay & timer that was set to a couple hundredths below your dial in and turned on the rev limiter at that exact time on the big end. No one would be likely to hear it down track as well and it would give the driver time to switch it off if they wanted too...

Curious, what did they find with the guy at Norwalk?

'70 Cuda,...605 EFI Hemi Street Car (6.20 best pass, 1.33 60ft)
https://www.youtube.com/watch?v=WYw6RA-k5Bk (6.25 at 108.75mph from inside car)
https://www.youtube.com/watch?v=3zQEb9uxFng (6.25 at 108mph from outside car)
https://www.youtube.com/watch?v=JCvfzsC4NgM (9.9)

'66 Barracuda AWB Stretched nose Blown 440 Car in build stage

'71 Duster Drag Car 400 Low Deck 512 best 6.002 at 115.44mph
https://www.youtube.com/watch?v=Znuo3jMUXTk