Originally Posted by dwielunski
All right, I have all data, 3G, 4G LTE, sms, mms on the ArtMod ROM.
-Factory reset and flash ROM in CWM.
-Flash Sprint ZVC modem.
-Edits in build.prop: changed product.model, name, device, changed region to US in a couple of places, changed wifi channels to 11 and ro.telephony.default.network to 8. Also copied the basebandversion out of the stock rooted ZVC. ro.cdma.home.operator.alpha=Sprint, numeric=310120.
I don't know if these build.prop edits did anything very meaningful, if I had to guess I would say it's the cdma ones that are important for data. But it is evident that changing ro.build.target_operator to "SPR" (was "OPEN"), the ROM sets up differently. For example, disables the brightness slider. The real significant change is that with operator "SPR" you are prevented from adding a custom APN. So you have to leave that as "OPEN". Unfortunately this means the lockscreen and notification shade say "Roaming Indicator Off" instead of Sprint. But I believe with the right xposed modules you should be able to overwrite those.
Anyway, with this setup, add a custom APN (I use quickshortcutmaker to access the APN settings, but you can also do it from terminal emulator).
APN roaming protocol=IPv4
I hope this is helpful on other stock KitKat ROMs. ArtMod is cool, a lot of G3 stuff baked in. Fonts still need work though so I have flashed over a Roboto Light mod for now. Hopefully the developer keeps up with it!
Much thanks @artur0588