So you’ve got a new MacBook Air 2013 with the all-day battery and the superfast PCIe based SSD interface, and you want to clone over from your existing Mac that you used to love but now feels underwhelming.

And you wanna take advantage of the fact that, unlike other any other operating system I can think of, you can just use a tool like Carbon Copy Cloner to move the entirety of your old drive in your old computer to your new one without missing a beat. (Of course, you could also use Apple’s solution, which is migration assistant; this generally gets you to about 90-95% of how things were on the old machine, but not 100%. And sometimes it doesn’t work at all. So that’s why I like cloning the system as if it’s set up just the way you like it.)

Here’s the thing: even though the new Mac appears to be running OS X 10.8.4, it’s not the same build number as the standard version, because it came out after 10.8.4 was released. For example, the standard 10.8.4 build number is 12C60, while the special build for the new MacBook Air is 12E3200. Eventually, the new Mac will run a standard build (in this case, likely to be 10.8.5 or 10.8.6), but until then, how do you clone if the new Mac won’t run the old Mac’s build, and the old Mac won’t run the special build? The answer is: it’s not easy, and I wouldn’t really recommend it unless that’s what you really want, but if it is, you can do it.

It’s easier if your old Mac has Thunderbolt or FireWire, and if so, then you’ll need a Thunderbolt cable or a Thunderbolt-to-FireWire adapter with a FireWire Cable. You’ll also need an empty thumb drive. If you don’t have Thunderbolt or FireWire, you’ll an external USB hard drive (USB 3 recommended) at least as large as your data on your old Mac.

The steps are:

• Make sure the old Mac is on the same version of OS X as the new one, such as 10.8.4. (If the older Mac can’t run it, you probably can’t perform these steps, and should instead use Migration Assistant.)
• On the new Mac, use Carbon Copy Cloner to copy /System/Library/CoreServices and /System/Library/Extensions to an empty USB thumb drive.
• Then boot the new Mac into Recovery Mode by holding down option and choosing the Recovery HD.
• Open Disk Utility and erase “Macintosh HD”. Rename it to something identifiable like “Sweet new Mac SSD”.
• Restart the new Mac, and hold down T to put it into Target Disk Mode.
• Turn on your old Mac.
• Attach your old Mac via Thunderbolt or FireWire (if you don’t have either, read below for instructions on how to use a drive).
• Open Carbon Copy Cloner (latest version) and select your old Mac HD as source and your new Mac HD as target.
• Select the Delete anything that doesn’t exist on the source option.
• Perform the clone.
• When it’s done, click the “Customize these Settings” button.
• Set the first option to “Left Untouched”. The checkbox doesn’t matter.
• Set the second option to Overwritten, and make sure the “Don’t Modify…” checkbox is unchecked.
• Click OK.
• Attach your thumb drive to your old Mac, and set it as the source.
• Clone /System (which should contain only Library/CoreServices and Library/Extensions) to your new Mac HD.
•  When it’s done, shut down both Macs and disconnect them.
• Turn on the new Mac holding down option, and choose the Recovery HD to start up from.
• Reinstall OS X to the new Mac’s HD. This will update, in place, the standard build you copied over from your old Mac to the special build required for your new Mac.
• When it’s done, you should be in business.

If you can’t use Thunderbolt or FireWire to copy files between your Macs, follow the same basic procedure above, except instead of cloning directly to your new Mac from your old one, clone to a hard drive instead. When done, attach it to your new Mac, and at the step where you reinstall OS X, choose the the external drive rather than the internal HD. Once it’s done, it should start up booted from the external HD; at this point, use Carbon Copy Cloner to clone the entire drive, to the internal HD, using the Delete anything that doesn’t exist on the source option.

Photo by raneko, courtesy Flickr Creative Commons.