Because of the varying selection of available ZF transaxles, it may be necessary to trim the input shaft.  This is not a critical operation, as long as the proper length is achieved.  The dimension at the right can easily be decreased by 1/4" without degrading pilot bearing life.

Note that the pilot bearing must be in a non-stock position, deep into the crank.  It also must have a taper to give clearance for the splined section.  See below.

A pilot bearing can be machined from an Oilite bushing (Boston FB1016-6).

The bushing is brittle!  Be very careful when putting it into the crankshaft.  Taper the small end (1.000" diameter on the drawing) a bit to make it easier to start, and be very gentle when tapping it in, making sure that you're using even pressure on the entire flange end.

 Pilot bearing