UPDATE...
Only Escalades and Denali's have LUX or Luxury stereo systems, ie. Radio, Amp, CD Changer, etc.
SLT/LT/Silverado/Sierra/Suburban/Yukon/YukonXL/Tahoe have the non LUX systems.
You can get a LUX head unit to work in a non LUX vehicle (and vice-verse) but Programming the radio from non LUX to LUX or vice-verse can NOT be done at a Dealer with the Tech2. There is something about the NAV radio programming that is proprietary, and only people with access to Delphi base programming can change the radios. A Delphi repair house (Specmo
www.spemco.com) can do it for a charge. But it sounds like your better off just getting the correct radio you need. There is a guy that was doing it for the website listed below for $75 plus shipping both ways. He no longer visits that forum, but his eBay name is supposedly maxpower_mi
Touchscreen model numbers
Newest revision LUX TNR-------15800001
Second Revision LUX TNR-------15230099
First Revision LUX TNR---------10377531
Newest revision non-lux TNR-----15800000
second Revision non-lux TNR---10379287
First Revision non-lux TNR-------10377287
Alt. Revision non-lux TNR---------15120706
Non Touchscreen model numbers
Newest Revision LUX INR--------15204335
First Revision LUX INR------------15204334
Newest Revision non-lux INR----15108241
You can read more at
http://www.dieselplace.com/forum/showthread.php?t=40437
I can make a good thread/write up and try to get someone to make it a sticky if you'd like... Instead of reading all 100 pages of the link (plus another 56 pages in his "part 2"