Why not just drill the 6V flywheel for the bigger clutch cover bolt pattern? Turn the flywheel a little and drill and tap the new holes halfway between the ones that are already there. Set the flywheel up in the lathe and scratch a circle with the cutter bit at the correct diameter for the big pressure plate, then drill and tap the holes. Lots of V8 flywheels have dual bolt patterns for different clutches.
Jerry

"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!