Amendment:
The KA24DE has an iron block instead of aluminum. The DOHC cylinder heads are however, aluminum. The engine was also producted in Aguascalientes, Mexico.
Automatic models also feature Nissan's "DUET-EA" system. A electronic link between the engine control module (ECM) and the transmission to facilitate smoother, more controlled shifts.
Additional Information: - http://www.nissannews.com/site_library/nissan/1998vehicles/240sx/index.shtml
Detailed Specfications (1997 and 1998 models): - http://www.nissannews.com/site_library/nissan/1998vehicles/240sx/specs.shtml