Swap Grounding Gremlins! Tips on SENSOR ground please

I've got a wire, Black with Light Blue Tracer, that I believe is the sensor ground. The single wire T's off at the manifold running to front and rear sensors. I'm not sure where the wire end came from. Because it's a colored wire I don't think it's a dedicated ground (ie the cruise has a dedicated solid black ground). Is it a ground that should feed back into the PCM? Thanks for any thoughts.
64 Cuda
Donor: 97 5.9 Van
Running stock EFI