Originally Posted by netomel
In the same process of downgrading you can stay on stock MK2 OR NB1.
Sent from my SAMSUNG-SGH-I337 using XDA Premium 4 mobile app
OP said he's planning to send it in though so it's best not to do any downgrade.
Sent from my SGH-I337 running BlackBox 3.0
Current Device: ATT Samsung Galaxy S4 (i337)
Droid Bionic (GSM Hacked)
HTC Inspire 4G (Desire HD)
HTC Dev Phone 1 (Dream/G1)