My son wants to install a 1998 civic engine in a 1994 civic. He has the 1998 engine which he rebuilt and a 1998 (P2P) ECU and determined he needs to leave the old harness in place. what type of conversion does he need. OBD2 to OBD1, etc? Went to ryewire but not sure which way the FROM:TO designation works. Can anyone help?