How to: Installing a DRAC on a 7730 ECM

I am using a speed density TPI unit on my s10. I have a 7730 ECU with a NV3500 trans. I wasn't able to find a write up on how to connect this transmissions VSS to the 7730 because the pulse is 40 pulse versus the 4000 pulse the ECM wants. What I have found and works great is the DRAC out of a early 90's suburban. I got my DRAC with pigtail at the junk yard for $10. So adding a VSS signal ended up costing me $10 and works good. If there was an easier way to do it let me know but this is what I found to work. I will admit Rbob over at Thirdgen told me how to do this. but Google showed nothing so I hope this helps someone.
Here Is what the DRAC looks like:
Attachment 9300
Here is a Diagram for the DRAC
Attachment 9298
I ended up Depinning The white wire and just taking off the cruise control connector I did not need either for my application. Then you have to add a pin to your Engine harness on pin C6 of the harness It currently is an empty pin on the harness. Then wire in your signal wires, 12+ and ground. If you have a Speedometer you will remove the speedometer wire from the harness and wire to the DRAC the pulses streams that the ECM creates and outputs will not be available.
Here is A picture of the wire I added to the C6 pin It is the one not cable tied in.
Attachment 9299

Now that we add the pin to the harness you need to tell the ECM to look for that 2K optical pulse not the 4k Magnetic. To do this in TunerPro RT on the $8D mask all you is uncheck the flag for "Magnetic speed sensor installed" Then I set the "Road Speed constant" to 2K.

Burn your new Prom install and enjoy. If you are reading this you probably know that the DRAC can be adjusted to work with different tire sizes. A lot of people will just solder on a dip switch But I don't like Dip switch they tend to burn up. Here is a link on how to do that if you don't know already. I got lucky mine is accurate as is.
Attachment 9301
Done!
PS ignore the rust, I might cut the floor pans out and fix it oneday:roll: I also have no knock filter don't judge!