100% of the electronics are different. in addition to the main board you have
Different Monitor resolutions
Different Power Supplies
Different guns
Different GUN IOs
and you'd need to wire up the gun LEDs around the monitor.
so yeah, you'd be looking at completely gutting the cab to do that conversion.
Options you do have:
Virtua Cop and Virtua Cop 2 would drop in there.
or Jurassic Park the Lost world if you upgrade your power supply as well.