hmmmm.....
an obd1 harness (EJ18) fits onto an obd2 EJ25 block with very little wiring....
All I had to do was take the harness off of the 1.8 and switch out the 2.5.
All the plugins were the same (except the temp sensor, the 1.8 was 2 plugs, whereas the 2.5 had 1 plug. simple splice there)...