i’m using a Engine loom and ecu (23710-74F01) from a 1996 200sx (S14) But with the added benefit of having it fully programmable.

Making the ECU fully programmable was done by using a device called Nistune with their Type 3 board. I bought mine via Pete at plmsdevelopments as i was looking for more than just one board. The board is supplied with the connections required and a base map installed (copy of the OEM map on ECU)
Nistune Type 3 Board

The fitting of the board was straight forward just open it solder up solder connector in and then plug the board in.

Then remove a component from the main ecu board.

Then bolt it all back together and it’s ready to go.