I'm looking into a 2004 v6 4x4 Dakota with a bad engine.
my question is what are my options for a replacement engine?

I found a 2003 with a V8 4.7l. could I simply swap that in? Or would I need additional comments?

 

Only thing that can replace a 3.9 V6 is the 5.2 or 5.9.

Only thing that can replace the 3.7 V6 is another 3.7 V6 unless you are electrically inclinded, then an 03/04/05 4.7 can be made to fit.

You may have the 3.9?, but 04 was the transition year I believe.

 

Thanks. Is there a combatible matrix I can consult? There also a 2002 with a bad 4.7L available locally. Would the same 2003 work in that?

 

Probably not. The 4.7 changed considerably in 2002/2003/2004 time range depending on the build date of the truck. Easiest way to tell, one generation has 3 connectors on the PCM (passenger engine bay fenderwell) and the other generation has 4. They're not compatible.

 

The '04 should be the 3.7.

The 4.7 should bolt in, the motor mounts/front axle mounts may be different though. Like Magnet says, the engine needs to be from a 4 connector PCM, the NGC version, truck. '03 was the transition from JTEC to NGC.

 

I couldn't remember if the 3.9/3.7 transistion was 03-04 or 04-05. thanks. So many damn changes! haha