Complex sentence: A09 and A11 were basically developments of the X Type with the Y Type Motor and converted to a four speed gearbox though some of the earliest A-Types had three Speed gearboxes from the X-Type.
Split into simpler sentences: A09 and A11 were basically developments of the X Type with the Y Type Motor. Though some of the earliest A-Types had Three Speed gearbox's from the X-Type.