Found a wrecked 2013 Ram 4x4 SLT 5.7 4x4, but it has 3.21 gears. Researching what I need to do to swap in 3.92s....

Front: Since it is welded, is it easiest to just by a used complete carrier set from a 2013 or newer truck? Any issues with axle shafts?

Rear: If I go with the OEM LSD, I can just put in a new 3.92 ring and pinion and be done, but if I want a Detroit TruTrac I would have to get a 2011 or earlier rear axle? Or is there a way to change one axle shaft so I can use the DTT?

I had bad experiences with my 2004 OEM 3.92 LSD, are the newer ones better?

 

Sounds like you have your hands full, and all great questions by the way. I am of no use to you on this matter, but please, let us know what you end up doing. I have 3.55's and would love to change them out.