crank pilot dia

how do you measure crank pilot dia ? buying a TCI touque converter, want to make sure i get the right size..1.375...1.250...1.848....?

torque converter for a c6 with a 460 states that there are different sized crank pilots,..1.375...1.250...1.848.. how do i measure the crank pilot ?

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

Thanks Guys!