So i tell them "The GM Helm manual says the radio can have the VIN Re-learned with the Tech 2 tool...."
They have the tech look at it and then they tell me they need to take the dash all apart for some numbers on the radio....and that it will cost at least $120...and they'll need my truck for almost a day! 
So I take it by the GMC dealership, whose only response was "Since its not GMC and you didn't buy it here, its $85 to diagnose"
It's the same truck!! 
I finally take it by the other chevy dealer nearby, and tell them that I need to have the radio unlocked. The tech actually was fairly informative, he said that there were 2 kinds of radios, the newer ones you have to have the numbers on the tag on the radio, and the older ones can be "re-learned" with the Tech 2 tool, and then the even older ones that can be just "unlocked".
I don't think any of our trucks use the newer style of radio since they're all pretty much pre-2004, so they shouldnt have to keep your truck for half a day and tear apart the dash to unlock a radio. Just thought I might be able to help someone out...
It took them about 40 minutes, but they didn't have to tear apart my dash and they only charged me $48 to unlock it.
I'm sooo glad I do all the work on my truck myself....sheesh...i wouldnt want to deal with any of the dealers around here....and i hope I dont have any warranty work any time soon
