Can I install Xposed framework and run GravityBox on stock and rooted Android 4.2.2?
Xposed framework is designed to work on all Jelly Bean devices and up. All you need to do is rooting the phone first. Similarly Gravity Box. There are 3 different variants like JB, KK, L which we know in Xposed modules store. In your case use Gravity Box (JB)  with latest xposed framework. A quick tutorial for future readers - Install Xposed installer > Install Xposed framework from within the app > Search for Gravity Box module and install it > Activate and reboot. That's it. Gravity Box is also available in Play Store.