Reg, I moved your post & started a thread for you in the 3x8 section, so that other V8 owners could benefit from your work.
To wire up these coils we have to know a couple of things:
1. Coil Fitment: You obviously have this sorted now, and the Prius coils do fit OK
2. Cylinder Numbering: See below and advise me if it's correct (As you know, I'm a V12 guy, not a V8 guy)
3. Firing Order: Again, please confirm what I show below is correct
4. ECU Ignition Capabilities: I'm assuming your Haltech only has 4 ignition outputs which, for a V8 engine, means you have to resort to a waste spark system. Please confirm your Haltech only has 4 ignition outputs?
5. Coil Pinout: The Prius coils are a "smart" design, meaning they have onboard ignitors, so we'll run a common +12 "rail" to all, and a common earth (ground) rail to all, then we'll pair up the trigger (ignitor) inputs.
Waste spark firing means that we pair certain cylinders and wire their coils together so that they fire at the same time. One coil fires on the compression stroke for one cylinder, while the other fires on the exhaust stroke for the other cylinder. Next rotation of the engine it's reversed.
So here's the Cylinder Numbering in your car, I think:
And the Firing Order:
And here's a wiring diagram of the Prius coils from Toyota. The colors aren't the same as the cut pigtails that you have, but the terminal numbers are shown, and that's what's important. This is the pinout of these coils when looking into the coil connector. Make sure you're clear on this - we're looking into the COIL connector, not the pigtail. Toyota are very good about marking the terminal numbers on their connectors, so look closely and you'll find them:
Pin 1: +12v
Pin 2: Not Used (this is the IGF, which Toyota uses for diagnostics)
Pin 3: Trigger (This is the pin used to charge/trigger the coil)
Pin 4: Earth
Next post I'll show you how to wire the coils up.