That year is kinda fuzzy as far as computerization is concerned. I know my '94 International 9600 was a Cat 3406E (electronic), the '92 was a Cat 3406B, thus mechanical. The Cummins family was a bit different in that area. IIRC (and do NOT hold me to this), the 5.9 became electronic in '99. I know the ISC is electronic.
Hope this helps.
Firearms stand next in importance to the Constitution itself. They are the American people’s liberty teeth and keystone under independence. — George Washington