Chances are that you have a 5.7L HEMI engine in your 2012 Dodge Ram 1500 & has the MDS, ( cylinder cut out )
If you find another 5.7L from a 2016 Ram 1500, the engine will fit
You will want to put both engines side by side
Then take the things like the Oil Pressure Sensor off of the 2012 & put it on the 2016 engine, then do the same with the water temperature sensor
Use all of the sensors from the 2012, that way you don't have to change your computers etc.
Usually you will want to use the 2012 Intake manifold too, but if it is the same height, width, length, etc. you may not have to to do that
Do not throw away the 2012 engine until after the newer engine is installed & running good
If the 2016 5.7L came out of 2500 or larger model Ram, it will no longer have the MDS, because they use a different Camshaft, etc.
Thank you for the reply. My truck does have a HEMI and it does have cylinder deactivation. I found a nice low mileage motor from a 2011 for less money and closer. I’ll probably just do that and be done with it.
Just make sure its from a Ram 1500, there are some differences in the other versions of the 5.7 to include the one in the HD trucks in the intakes and cams. A 2009-2018 engine will work for you, 2013s and newer will have some differences in the accessory drive as they went to electric power steering from hydraulic in 2013