OP wrote above:
[[ When I go to install Mavericks will it format the drive then, or do I need to get a whole new drive? Any advice would be great! ]]
Before you go through all the trouble of opening a newer iMac (which isn't designed to be opened), why not just take your SSD and put it into an external USB3 enclosure, which you can buy for about $18 ?
Advantages:
- Will take 90 seconds to put drive into enclosure and connect it to iMac vs. quite a while to open the iMac
- You don't risk damaging anything inside
- You won't have any problems trying to get the cases back together
- Most importantly -- you won't notice any speed difference between running the drive externally vis-a-vis internally.
Disadvantages:
- You won't be able to enable TRIM via USB3 (however, this probably won't result in much of a slowdown over the long term, all-but un-noticeable in day-to-day usage).
Aside: if you spend more $$ for an external thunderbolt enclosure, you WILL be able to use TRIM. Whether the additional cost is worth it, only you can decide.
Some folks have used a piece of velcro to attach the external enclosure to the back of the iMac's stand -- off the desk, out-of-the-way, out of sight.
There's no law that says the boot drive -has to be- inside the case.
The iMac (or ANY Mac) will run as well when booted externally....
Here's a USB3 enclosure to consider:
http://www.amazon.com/Optimized-Ina...0360474&sr=8-1&keywords=inateck+usb3+2.5+uasp