delete o2 sensor delete. efi set up
I assume you mean REAR 02 sensor delete? Because EFI needs the fronts to properly work.
How invested are you in ignition right now? If you wanted to, rather than using a distributor you could convert the engine to DIS using the cam sensor, bracketry and wires from a 96-01 Explorer and use your stock 4.6 coilpacks and computer to run the whole setup with a custom tune. That kills quite a few birds with one stone - NO new ECM, NO rewiring of the harness going to the ECM(connectors and wiring between EEC IV and V are totally different), Controls the 4R70w, reuse packs, and have much stronger and reliable spark than any aftermarket dizzy setup. That's how I'd do it