i know this seems like a noob question.  But i order the 2.7 Pulley from PCFY, i went to have it installed today and the mechanic said its the same size pulley thats already on it.  The stock 2.8 inch pulley.  I put the pulleys next to eachother and they were the exact same size.  And yesi looked at the rib part and the outer edge as well.  I couldnt see any noticeable difference in the size.  The package did say 2.7 and so did the reciept.  So is it just to small of a difference to notice, or did i get the wrong pulley from them?
2006 Black Cobalt SS Supercharged G85
13.91@102.77
 
enough to tell the difference side by side.  send it back.