Hmmm....it looks like identifying a '68 SS by the VIN only applies to Chevelles. However, there are other clues that may help.
I found a couple links for you. Google is a wonderful search tool.
http://www.camaros.net/forums/archiv...p/t-23174.html
http://www.camaros.net/forums/archiv...p/t-25574.html