I was going to go with the ACT HDSS and Streetlite Flywheel (12.5 lbs). I decided to go with the Prolite flywheel (8.8 lbs) and they didnt have the HDSS in stock so they sent me the XDSS for no extra charge. Unless you have a hydro clutch (3rd gen Integra), don't get the XDSS. Its pretty hard to push in (like 80%increase in torque capacity). Go with something from ACT.