b16a with b18 ecu??

i just bought a 91 integra that someone swapped the b18 for a b16a which would have been ok if they would have changed the ecu as well..would it be possible if i changed to b16a ecu to repin the b18 harness to work,,or just need to get harness as well??

All you need to do is since its a 91 get a obd 1 to 2 subharness, plug in your b16 ecu n run your vtec wires. If I'm missing something someone please let me know.