2001 chevy express van, viper 800hf, 551t

I am finally down to the questions I can not find answers for... I have a 2001 Chevy Express Cargo Van--it's a stripy. I am installing a host of DEI security components including the Viper Ultra 800HF and a 551T Valet remote start. I have found the two wiring location lists for this van on Web and they have been hugely helpful.

So what I would like to know, rather than assume is:

1) Does anyone know if there is a Neutral Safety Switch wire in this van, or how to search for it? The lists I have don't include the location of an NSS. The DEI install manual says the GM Express vans do NOT have one and that I need to use the brake wire and some wires at the ignition along with a relay and some diodes in place of the NSS.

2) The lists both say that the Tachomoter wire is under the hood, under the VCM (what is a VCM?). Is the Tach wire in the Diagnostic plug in this area? Or does anyone have a better description of where to find this wire?

Thanks for any help you can offer!