Explorer would be a little too heavy for the 4 banger, 100hp is what '90 2.3l had
Smallest engine used in an Explorer was 160hp 4.0l OHV.
Can you do it, sure, should you do it, no, you for sure wouldn't like the results
You would need a 4x4 trans from a 2.3l Ranger, 1997 Explorer would have BW1354 transfer case, same as Rangers, so thats fine
Explorers got the BW44xx series in 1999 and up
2.3l 4x4 Rangers were not common but were made until 1997 I believe.
You also have to get clutch brake pedal assembly for Explorer, and steering column to get rid of auto shifter
Weld a cross brace for 2.3l engine mounts
maybe different 4x4 oil pan and oil pickup.
You are changing from an OBD2 system in explorer to an OBD1 system when '90 2.3l computer comes over not sure what wiring issues would follow that