Hi JMOR,I suspect the jig numbers are correct, but measured from the edge of the connector ball, not the middle. Would have been consistant for the book to have given values to the edge. 😃
The 2.450 on the jig with a .020 gasket = 2.47,,, which is the long demension.
My 2.56 isnt too far from spec, and it works, no overspeeding.