stuck with 0MPH...HELP!

[77c10]

I've been working on this for a few weeks so I would love some help.

My setup
LS3 from 2013 Camaro SS
t6060 with t56 magnum conversion
Dakota Digital Gauges
on my 2nd e38 ECM trying to solve this issue.
DD GPS-50-2 wired from speed 2 to pin 71(also tried 72)

I have gotten the gauges to read perfectly using either the VSS from the trans or the Dakota GPS module
No matter what setting I use I can not get anything but 0mph on the log. Currently I'm trying to use the GPS signal since I can change the pulse setting from 4k to 128k. Please any help or something to try would be appreciated.