I noticed that too Tom210, when My Dad and I converted "The Defect" ('77 aussie 120Y 4 door sedan) from a 3N71B ( 3 speed auto), to a F4W60L car ( 4 speed manual) we also noticed that there is only ONE way that the flywheel will fit! - otherwise the bolts don't line up!, there are TWO different crank spiggot sizes too

even though "the Defect" is a manual now it has the auto AND manual spiggot bushes as I had Dad machine the flywheel to the larger spiggot size - and so it would clear the auto spiggot bush- Yes, The auto spiggot bush is still there to ensure that the flywheel doesn't go "on a holiday via leg"