I wonder how complicated it would be to swap a 6.4 crate motor into a 2003 ram that has a 5.7. I assume the motor swap would be pretty straight forward but I wonder about the tranny and ECM. Like most guys money is a big consideration. Might be cheaper to just build the 5.7, don't know. I have a 2003 SLT Sport, 2 wheel drive with 3.91 posi. I bought it new and it's in great shape, got 90,000 miles on it now. I'm not in a big hurry to do anything but in the next few years I'll need to think about a new truck or spend some money on this one.

 

One major issue would be to find a PCM to run it, as your 03 one certainly wouldn't!
That would mean a completely new/modified wiring harness.
It would also be the case in modifying and rebuilding your stock 5.7 to any major degree as well.
A stroker 392 for instance.
Anything more than a 260 cam, and specialist tuning is needed for 03's which the PCM won't allow without other modifications.
03 PCM's do not have an idle RPM adjustment along with a separate transmission controller as well with no shift point adjustments. People have a "get around" solution, involving pulling the power steering sensor on the rack and other stuff. This lifts the idle RPM's somewhat, to allow 268 and greater cams, to idle. But they're still notoriously difficult to tune.
03's are known as "the red headed step child" of the Dodge family lol.


Al.

 

Are you talking the older style 6.1 based 392 from Mopar or the new production 392? There are some major differences, including tone ring if I'm not mistaken. As abarmby said, tuning will be the big thing here. The stroker with worked heads would make packaging easier, but tuning is still the issue.

 

First step to perform the swap is to go to Autozone and buy a new steering wheel cover

Then you take that cover and put it on the new 2014 Ram with the 6.4 you just bought.

BAM, swap complete.

 

Sounds like I'd be better off to buy a new truck. Thanks for the advice.