Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.
That is different !

C2D will fit fine - the only thing to check is that the replacement heatsink has 2 "horizontal" connectors for the heatsink sensors. Your existing heatsink will have 2 "vertical" connectors. The fans are the same on both models.

Go for it - the Core 2 models do run quicker and cooler and you should see about 25% improvement overall (and you can increase the RAM to more than 2GB).

You will also need a V2 topcase because your Core Duo one will not work with the Core 2 logicboard - so add that to your shopping list !!
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.