I had one installed (Fidanza) along with ACT HDSS clutch some years back, but I always wondered if the flywheel was installed. I knew the clutch was by the behavior, but the flywheel did not feel lighter to me. The motor didn't feel like it was revving any faster. I did get the original parts after the install, but IIRC, the kid that worked at the shop was let go because he didn't complete some of the work [didn't install all parts]. I can see the flywheel from the bell housing, but didn't really inspect it to see if it's the Fidanza piece. I guess I have to jack the car up and remove the undertrays to see... Is there any other way to check?