Which wire on the LMs is considered the ground for the LM? I see from this link, http://minimopar.knizefamily.net/ecu/lm-1987-t2.html, that red 24 and 25 are Signal ground source from fuel rail bolt and Signal ground to sensors respectively. Also, there are two grounds on the blue connector on 7 and 8, Power ground source from fuel rail bolt.

I'm trying to get a better ground for my wideband to rule out any issues there, so which ground for the LM is best?