Maximo,
Its a mugen flywheel.

Wingracer,
Grinding on my BCE chassis is not an option I am willing to explore.

You just have to open up the holes a bit. You probably only need a couple mm. Once the mount is on you will never notice.

you need to get a different flywheel. i have different flywheels just for this reason. you may also need a shorter pilot nut so the clutchbell will line up with the spur gear.