Two different VSS entries - what do they mean?

[davepl]

Under Speedo in my LS3/E67 I see two entries:

VSS Pulses Per Rev: 40
VSS P/Rev Trans : 36

They sound the same as do the status bar tips. And yet the value are different. So, two questions:

a) Can anyone explain the difference between these two and why they have a different value in the stock calibration?

b) If my TKO-600 has 12 teeth per rev on its VSS, what do I set these two? I'd think both go to 12, but I don't know yet...

Thanks,
Dave

[davepl]

Anyone? I do need to set this - I ordered the eRod automatic calibration even though I'm running a TKO because I knew I had to change this anyway, but I need to know why they're different before I can just stomp values in there...

[LSX378]

GM speedo settings can be a black art. One may refer to wheel-speed sensor teeth. They are almost certainly auto settings, so try 12 in both if thats what you have.