Well, yes, the engines are more the same than different, yet there are differences.

http://www.grandprixforums.net/f17/t...lots-7763.html

But just as a friendly warning I have only seen a couple people on this forum actually pull off a top swap on a 04+ and actually have a running car a year later. I have read peoples accounts, and it doesn’t sound like fun at all to be honest. IMHO get a PCM tune, slap on a set of 20s and be happy.