Does anyone know if the GREEN/BLK wire (from the VSS), used for the electronic dash speedo is present in non-digital dash Firebirds of the same late 80s era...

I've not taken the dash apart yet so I'm not sure what's behind the Analogue dash...

If not, can anyone tell me where I can source the correct signal from as I know there's a signal to the tachnometer from the VSS buffer (a brown wire I think) but I don't know where the buffer is or whether I even need to source it from there...

Help me, please!!!

-by the way, I'm looking for schematics for the analogue dash to compare with the digital dash if anyone knows where they are online ??

thanks