Electronic speedo help please

[Thekids68]

My son and I have put a LT1 /4l60e in his 68 nova and the problem i'm having at this moment is the speedo says its not getting a pulse. I just put in a new VSS and still the speedo wont work. I'm using an aftermarket harness from the fuel injection connection and the wires are labeled to there locations. My understanding is the speedo signal to the ecm also controls the shifting in the tranny. Does anyone have any ideas on what I should check or am I missing something for this VDO Electronic speedo? All ideas welcome Thanks