3,1 2008 Upgrade to 3.2 8-core
I had trouble finding info on this so I thought I would add some here for future folks trying this out.
I recently got a 3,1 for GPU testing. I saw a pair of 5482s going for cheap so I jumped. They were $240/pair. I expect to get a fair amount for the old 2.8s since I can list them as REAL APPLE !!!!
Anyhow, taking a 3,1 apart is similar to 1,1/2,2 with a couple important differences. As noted by a guy at XLR8yourmac, the Obstruction Department at Apple decided that the 1,1 was too easy, so they added a screw to the front fan cage. It is down low and runs parallel to the length of the machine. EVen after you loosen it, it has to come out. The fan itself could then IN THEORY slide out, I had to use my Metric Hammer.
In addition, there is a tall heatsink for the chipset right next to CPUs that I don't believe is present on 1,1s. It requires 4 scres be removed, 3 of which are easy to see, and one which is scrunched behind it near base of CPU heatsinks.
The CPU heatsinks are held with screws that can be removed with a T15 Torx or a 3mm Hex (or so I've read).
The initial steps to get to all of this are a royal PITA. Apple clearly wants you to never, EVER do this. Jerks made it difficult and dangerous, lots or sharp sheet metal ready to slice your hands up like bologna at a Deli. I was able to remove the RAM cage and finally realized that the trick is to push the grey plastic things at either end INTO the RAM cage. There are little clips that I used a thin metal ruler to unhook. The metal frame around the heatsinks has magnets that help clip it in.
I am amazed that Apple went to so much trouble to make drive and RAM changing easy and intuitive and then made CPU removal into a mine studded obstacle course. Not very nice of them.
On the plus side, once I got it all buttoned back together it booted up first time, no problem.
If you decide to do this, may as well add or update your Airport card. There are 3 antenae versions that are 50% faster then original Apple units. (Run at 450 instead of 300). There is a 3rd antenae wire already there waiting for it. Getting the fiddly antennae wires on is easier if you connect them BEFORE screwing card down. I found these available for $20-40.