The obd1 distributor has 2 plugs, the obd2 distributor has 1 plug. If you want to use the LS wiring harness, you can. You can also use your stock one. If you don't already have an LS harness, I would recommend that you just use your stock one. Either way, the LS ecu will plug in. Or if you choose, you can also use a 92-95 DX ecu and it will work just as well. Your going to spend more money on an LS harness than what you would lose if you charged somebody less for a swap w/o stock wiring harness. I'm not sure if the b20z has the same IM as the b18b. If it doesn't, then I suggest you get an OBDI b18b IM, TB, and injectors. The obd2 injectors have different plugs than the obd1 counterparts. The actual mechanisms are the same, but the plugs are just different. So you have 2 choices: 1. swap the injectors or 2. swap the plugs.

I have never physically done a 5th gen swap, only 6th gen. I will be tackling that soon though. I'm putting my old OBD2 d16y8 into my 92 CX hatch. I am using the stock harness, obd1 injectors, and obd1 distributor, and a p28 ECU.