I thought the same thing Jeff. When GM was transitioning to the gen 4 platform, it was a sloppy transition because there were a lot of motors with and without AFM/VVT designs. I read a quote in an LS book that I have from a GM engineer who said that the move from gen 3 to gen 4 wasn't a cut and dry move, it was spread out over a few years and models. I'll find that quote and post it later. On a more relevant note though, if the OP wants a more educated guess, we're all going to need more info about each motor and maybe pics also.
Quote Originally Posted by Lextech View Post
Wouldn't the 2007 have a 24x crank reluctor and the 2008 have a 58x crank reluctor?

Jeff