Positive rear end

[bry1]

I have a 2018 dodge ram 4x4 slt,, I also have a 2005 and 2004 dodge ram slt, both have posi rear ends my 2018 doesn't have posi (limited sleep), I hate it immensely!!
Can I change out the gears and bearings to make it posi or will the 2005 or 04 rear end bolt up under my 2018 ram?
I'd prefer to rebuild it instead, if possible?

 

[2003F350]

I would say yes it likely can be done if yours truly came with an open rear, since it was an option. I don't know if it's going to cause you any programming issues though.

 

[Different Drummer]

I believe that there is now a "Toesen" style LSD kit available for the rear axle used in the RAM 1500.
Why not simply install one in the 2018. Probably less hassle and reasonable cost than swapping things around. Then you will have the LSD in both trucks.
I have the factory LSD in my 2017 and am happy with it. However, if I were given the choice I most likely would have chosen the "Torsen" style over the clutch style.