Hot Rods Tpi-tech instruments

It appears TPI-TECH is out of business and can't help with a problem.
I can't get my electric speedo to work on a new build. Can't figure out where to pick up a signal from my 4L60-E transmission. Any help surely appreciated.
Thanks
Nashrumble

 

Do you still need help with this? I have a TPI speedo instruction sheets. I am using it in a TH350 so it uses a gear driven sender to send the signial to the gauge.