VSS & Cable Driven Speedometer after LS Swap

[brandtjohnd]

Hopefully some of you folks who have been down this road before can chime in!

Background:
I am replacing the factory AMC 360 and 727 with an LM7 LS motor and 4l60e. I will be keeping the NP229 transfer case. My plan was to use the cable driven speedometer with the "Sensor, vehicle speed, (VSS), GM, 8k PPM, cable through version" from Novak Conversions. This would allow me to know the speed of the transfer case output shaft. The original Speedometer and the PCM would each get their respective signals and be happy. The PCM needs a ground signal when the vehicle is placed in 4WD so it knows the vehicle is geared down by ~2.7. I've planned this out as well.

On Novaks site they say this about the VSS Cable Through Sensor:
"Note that the above products are not appropriate to rely on for the purpose of shifting an automatic transmission (such as the 4L60E) when a gear reduction transfer case is being used, since when the transfer case is shifted into low range, the vehicle speed will read between 2.0 and 2.72 slower than the transmission output shaft is actually going."

The question is this:

Is my plan to use this sensor totally off? Or is there another way to retain the factory Speedometer and give the PCM the VSS signal it needs while in 2WD or 4WD.

Thank you,

[babywag]

GM uses a VSS in the transfer case and a 4wd low signal switch so the pcm knows when it's in 4wd.
If wired and the pcm is programmed correctly you won't have an issue.