Originally Posted by BLACK94SSEi
The only way I would take it to a GM dealer, is if they will Honor your warranty,
If the place it is at right now is giving the owner a hard time, a second opinion may be needed. The costs should be able to recovered once the repair and issue is vetted out as not the owners fault.
A GM dealership with intimate knowledge of these engines would be the place of choice. If the issue goes to court, GM Dealer will be looked at as an expert whereas shadetree mechanic would be questionable.