These competition flywheels to suit MG B series engine are machined from chrome moly steel with an integrally cut ring gear for the lowest possible moment of inertia. They are designed to allow the use of 7 1/4" (184mm) step fitment competition clutches although versions to run the O.E. 8 1/2" (215mm) clutch is also available.
The clutch mounting holes are tapped M8 please refer the associated products link below for suitable clutch to flywheel mounting bolts.