I would grind a bit off the clutch-disc hub myself if you just need the bit of clearance it sounds like you need. you have already added a spacer

30 seconds with a 4.5" grinder vs a 15 minutes with a die-grinder and the posibility of adding a stress riser to the input shaft.

Just my $.02


The problems we face today can not be addressed at the same level of intelligence we were at when we created them - Albert Einstein Or with the same level of $ - Me