just need vss on 08 superduty, no gry/blk at radio harness, guessing it might have switched to canbus.

Most likely is can bus. You don't need it to use it with the D3 anyway. Which radio are you installing?

doing a D3 but the customer wants vehicle dynamics. Gonna try a can-vss once i get it in

The vehicle dynamics work in my '06 Zephyr and I did not hook up the VSS.