Wiring modifications needed to make it all work;I used a number of references to get as familiar with the ford and miata wiring as possible. A few of these references are; the ford motorsports manual for EFI Engine Management Harness, Corral Forums 4 banger to 5.0 efi write up, RJM Injection Technologies EFI Harness Installation Manual, 88-91 EEC Wiring Diagram by tmoss and the miata wiring diagrams from Yorba Linda Miata.The ford computer requires a constant 12-volt source. I ran the black/orange KAPWR wire from pin # 1 on the ford computer to the 80 amp fused connection in the miata fuse box. To provide the keyed 12 volts to the computer and harness, the white/red wire found at the miata computer connector (#1B) is connected to both the gray/yellow HEGO wire at the green eight pin plug near the ford computer and to the red/green wire at the EEC relay. The red/blue wire from the TFI needs 12 volts during starting-I spliced that to the starter circuit violet wire.To allow the miata tach to function properly, I attached a lead between the wire going to pin # 4 on the ford computer to the yellow/blue wire found on the miata igniter plug (passenger side).To have a functioning MIL I connected a jumper from pin # 17 on the ford computer to the yellow/black wire on the miata computer connector (#1E).My ford harness did not have a provision for a fuel pump relay so I used the miata relay. I used a jumper from pin 19 to the miata blue/red wire at the miata relay. This is for the fuel pump monitor loop that the ford computer needs to sense that the pump is on. And the relay grounding circuit is comprised of a splice from pin #22 on the ford computer to the lt-grn wire at the miata relay. The beauty of the computer controlled ground circuit is that it senses the distributer rotation to close the circuit otherwise it opens after a few seconds shutting off the pump.Starter connections are intuitive if you use a PM starter.Electrical grounds; the ford harness I have needs to be grounded to the body at three different places. One is by the coil connection, another near the firewall grommet and yet another next to the computer. A good ground between the engine and the miata body is critical and make sure the battery is provided with a solid ground to the body as well.Alternator wiring is very simple, especially if you use a 3G alternator like I did. There are only two splices to make between the miata harness and the ford 3G alternator. 1. The original large gauge white miata alternator cable with the eyelet is simply attached to the (B ) stud at the back of the alternator. 2. The two splices required are the two smaller gauge miata alternator wires that need to be attached to the 3G voltage regulator plug. The small gauge white/black miata wire is attached to the ford green/red "I" wire and the smaller gauge white/green miata wire is attached to the ford yellow/white "A" wire. The center white wire on the ford voltage regulator plug is the "S" stator wire and gets plugged back into the rear of the alternator with a spade like stator plug.