Daemongar: Confirmation: ACT flywheels must be machined, you can't replace the friction surface when you do a clutch swap. (“From the horses' mouth”, so to speak.)
Promo on http://www.prostreetonline.com/ : Finally, ACT offers eXACTly what performance enthusiasts need: all the benefits of a premium quality light weight flywheel at an affordable price. ACT currently manufactures XACT flywheels in two versions, ProLite for road racing applications and very quick throttle response, and slightly heavier StreetLite for street and drag racing vehicles which may require more inertia. For example, the Integra ProLite weighs 8.8lbs and the Integra StreetLite weighs 12.5lbs.