MACH II Button CFAs offer lower Moment-of-Inertia (MOI) than MACH I CFAs, without sacrifice to reliability. Ideal for applications that allow 5. 5"clutches, such as many asphalt Late Model series. In addition, MACH II clutches accept competitor's cover-mounted ring gears and can be used within their rear-mount starter bellhousings. All MACH II CFAs include clutch assembly, discs, buttonflywheel, clutch-to-flywheel bolt kit and flywheel-to-crank bolt kit. Lightweight and Ultra-lightweight flexplates are available.Pit Stop USA offers Sonic Mach II 5.5" Button Clutch Assembly - 3 Plate - 1-1/8" x 10 Spline - SB Chevy V8 (E) 11005 at low everyday prices. Be sure to check out all of our products from Sonic Racing Products including Sonic Racing Products 3-Disc 5.5".