So I have one of the last 5.9 magnums which means I was looking in the 2nd gen for this answer but it involves a 2003 so I'll try here too. I have a 2002 Ram 1500 5.9 magnum 4x4 quad cab. I am rebuilding the engine, airgap intake, engine quest heads, hotter cam, didn't stroke the bottom but bored. 2, decked and honed the block. I am finishing up that part but am thinking of switching to a 2500 body instead to improve the towing capacity and payload.
I want to retain the 4 doors of the 2002 1500 which means a 2003 2500. I'm not finding any 2003's with the 5.9 magnum so how hard would it be to take a 5.7 gas or 5.9 diesel truck and mount my 5.9 magnum in it? I'd have two trucks so I can swap parts to make the best combination of the two but I'm looking to move my motor to the 2500 chassis so that's where it starts. Are we just talking about a couple of engine mounts or is the 2003 not at all set up the same? I know the 2002 1500 has a mount on the transfer case so that's my first thought that this may not work.

 

2002 2500 is still considered a 2nd Gen truck. You won't find one with four door handles. Needs to be 03 or newer.

 

yes, I've figured that part out. So the question is can i put this 2002 5.9magnum in a 2003 2500 without a big hassle? I was certain the 2003 2500 had the 5.9 gas as an option but I'm starting the believe I was wrong about that two. If it's more than just swapping a couple of mounts and bringing the transmission from my current 1500 then >'ll probably leave it alone. Finish my build and if I really start to need the heavier hauling I'll get another truck then.

 

From what I am seeing, the 5.9 gas didn't make it into the 03 or newer heavier trucks. I don't know how much the electronics change from 2nd to 3rd gen, but, I would not be at all surprised to discover the two are not compatible......

 

I highly doubt they're gonna work out as well...

 

2003 HD's did not have the 5.9/360. The only engine options for the HD's that year were 5.7, 5.9 diesel or V10. 2G and early 3G elex are not at all directly compatible (later 3G was CAN so definitely not).