I shifted at or above 7000 RPM after testing a bunch different shift RPM
I dyno tested that motor several different times on several different engine dynos, two different DTS and s Studka dyno, that motor made peak HP at 5500 and 5600 RPM with the six pack and it made peak torque at 4500 and 4600 RPM, depending on which dyno
I tried shifting it at 5500 RPM and then 6000 RPM, it ran faster at 6000 RPM so I then tried 6500, then 7000 and then 7500 RPM, it ran quicker and faster the higher I shifted that stupid motor I got scared of it above 7500 RPM so I decided 7000 to 7300 RPM was good enough for me It would repeat ET real well at those RPMs
That was a good car, lots of fun, especially on the street