The OTA will likely fail because the alternate kernel changes the checksum and the update will quit. I was running faux123's kernel and flashed the stock kernel, but the manual OTA failed. I had to download the stock image and manually flash the boot.img and system.img and that broke root on its own. I then rooted, ran Rootkeeper, flashed up to 4.2.2 and the restored root. It was a hassle trying to sort out and ate up a few hours I would've rather used for other things.