I thought this question would have already been raised & answered by now, but I searched and searched.

What's the difference between the 04MY injector wiring harness 4C3Z-9D930-AA, and the 05MY 5C3Z.... part? Are they interchangeable?

I think there is also an even older 3C3Z part, but I understood this has been superseded - maybe this was the old version without the angled FICM connectors?