My dodge dealer replace my 5.7 hemi in a 2004 Ram 2500
with an 5.7 engine for a 2004 Durango. Bad mistake!
runs like crap, no power and poor gas mpg
original engine dropped a valve on the expressway and wiped itself out! was getting 15-21 mpg, new engine does good to get 15 mpg
New engine was OE Mopar reman # RL025381AA
parts book calls for # R2857034AA
someting has to be different in these 2 engines [ WHAT?]

 

Shouldn't be a difference between tem once your accessories/manifolds etc are installed. It's the same engine.

 

Only diff between 1500 and 2500 is later on when MDS came out.