Root for 4.4.2 is possible - if you flash the stock ROM as a zip file in custom recovery from 4.2.2 (which will be overwritten after the flash)
then you can directly flash the supersu zip:
1. boot into 4.2.2 custom ROM
2. install 4.4.2 zip and don't reboot
3. install supersu zip - don't reboot
4. wipe data, cache and dalvik-cache - then reboot
For zips you can use the forum-search function
There's also a custom boot-partition which enables to stay on the old custom recovery, but that's only made for B-Devices...