morgan runs it on his 4th gen, as does Jay and a handful of fellas on DT
It'll work
It will work, yes... BUT it's not anything that you're gonna feel. In your current state, consider it a safety thing if your truck develops a reason to over heat or something. Having a 20* window in your pocket is nice sometimes. I am unsure what the adverse MPG effect is going to be on the 5.7 ram, but I do know that it clipped me for right at .4 MPG across the board.
All in all, going to a lower stat is a complimentary mod. It flows nicely with heads, a cam, tuner, and usually a stroker kit. Outside of those, it's really not worth toying with in my book. Also, you will notice a longer delay in how fast your truck heats up in the winter time as the truck will be dumping cooler water and coolant to the motor sooner than you are now. In these trucks, I doubt it will be anything really noticeable because I have noticed that my auto climate control when on heat will kick on when the coolant temp reaches 100*F. (Auto set to 73*F as well)
Enjoy installing the mod though. Looked under the hood the other day and Dodge finally got around to making the stat stupid simple to install. I know on the 2nd gen magnums, you had to unbolt the AC compressor and swing it out of the way a bit before you could get to the thermostat.
EDIT: My bad. You had to swing the alternator out of the way if you didn't have a 1/2" drive extension. The AC lines had to be moved instead of the compressor.