Hi,

I have actually done this motherboard swap. I upgraded a 2.4 GHz 1226 to a 2.5 GHz 1260.

It is not a straight swap. You will also need the heatsink from the 1260.

It does not stop there though. If you want this to be as pain free as possible I would also suggest obtaining the bottom case from the 1260. There is one screw hole that for the motherboard and heatsink that is slightly off from the bottom case of the 1226. The rest of all screw holes, and clips, mounts, etc are all the same.

On the replacement that I had done, I used a dremel tool and opened up the holes on the motherboard and heatsink just slightly. I have been doing this type of thing for many years, and felt very comfortable with such a task. Many are not, and in hindsight, I do think that widening a hole through the heatsink is not necessarily a "most brilliant" maneuver, and I think if I ever do this again, I will get the other bottom case.

BTW, the machine in question, is still running like a champ 15 months later, without any issues.

Hope this gives you the information you were seeking.

Cheers

Murias