911 04 silverado stereo installation

[onelow04]

I have a 04 silverado that does not have onstar or the bose system. I have been told by several stereo shops that since I dont have either of those that I can just buy a standard stereo plug (best kits brand bha2003) which fits the new cavalier and it also plugs into the silverado harness. The only problem with this is that I will lose the chime and that I will have to run a ignition/acc wire. I talked to one guy who said he had his like this since he bought it in 03 and has had no problems. I dont care about the chime but some people has told me that on the 03-04 models that it will mess up the bcm. Can anyone help with info on this?