Like I say they are pretty tough. I had 65 runs on that motor last year shifting 7400-7500 rpms. Turned it 8K once when the shifter malfunctioned, and it was on the chip in a heart beat, no kidding. Engine was a 557" Indy Maxx block, with plenty of compression and running alky injection....
Pulled a best of 1.07 60ft...Even though it was a digger, that's a getting down the track.
Ran consistent 141-143 MPH in the heat it went a 144..
Just wished the guys who built it know ed how to tune a little better