Just a few thousandths of runout in the bolt circle of that drilled and tapped flywheel will set up a harmonic vibration at certain RPM's that will rattle the fillings out of your teeth. That pressure plate weighs several pounds. If you choose to do that, find a REALLY good machinist!

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!