http://zr1.net/forum/showthread.php?t=9763&page=2
That should explain a little... some folks get pretty heated and defensive when I bring up the issue, but when you are buying so-called ACDelco parts, it's best to check on the return policy beforehand... there's lots of "white box" parts out there, some may be legitimate ACDelco parts, but I have my doubts about some. The vendor in question in my case was Partsladi on ebay, who is no longer in business...
