Considering swapping logic board from SGH-M919 (T-Mobile) to SGH-i337 (At&T), need advice.Can I get some help?

A

AC Question

Considering swapping logic board from SGH-M919 (T-Mobile) to SGH-i337 (At&T), need advice.

I have had my unlocked SGH-i337 (AT&T) for a while and I love everything about it. The only problem is that I am on T-Mobile network and am therefore unable to take full advantage of the phone's capabilities (Wi-Fi calling, Visual Voicemail, and most importantly, being able to switch on voice and data roaming) ...

Not being able to have Voice and Data roaming is a huge hindrance because I am unable to take advantage of T-Mobile's free roaming and therefore lose reception when traveling outside of T-Mobile coverage area.

A friend recently gave me his old SGH-M919 that is T-Mobile branded, and therefore has access to the above-mentioned features. The only problem is that the body of the phone is pretty rough shape and the phone is running on Android 4.4.2 whereas mine is still in great condition and runs on 5.0.1

I was wondering if it would be advisable to swap the logic boards of the two phones to optimize form and function of the unit that I am to keep.

Please excuse my ignorance on this topic as I am a noob when it comes to these matters...I am just looking to get optimal performance out of my phone.

Thanks in adavance!!!