When it comes to the mass production cast 460 crankshafts:
  • 2Y crank is 1.85" pilot diameter
  • 2YA crank is a 1.85" pilot diameter
  • 2YAB crank is a 1.375" pilot diameter
  • 2YABC crank is a 1.375" pilot diameter
  • 3Y, 3YA cranks are a 1.375" pilot diameter
At least this is how I understand it should be, so no garantees. Note that the change from the larger 1.85" to the smaller 1.375" starts at the 2YAB cranks. Who know's, there may be some very early 2YAB's that have the large hole...I've never seen one, I'm just saying...

Paul