I recently changed the clutch and flywheel on my 96 GS-R with a Exedy Stage 1 and ACT Streetlite Flywheel. I did the proper break-in procedure for 500 city miles, but now I am getting a loud vibration between 7k and redline.

The car or engine does not shake, but it is very audible from inside the car. Also, I can actually feel the vibration in the shifter... when I grab onto the shifter, it dampens the sound. I do not hear or feel anything at less than 7,000 RPMs.

Any suggestions?