I have a 2002 Dodge Dakota Sport with the 4.7L Magnum engine ad I'm needing a new engine for it. Would it be possible to do an engine swap for a 2004 5.7L Hemi Magnum since I've heard they have matching bolt patterns, with the only things I'm needing to change is the wiring harness?

 

There are multiple threads on here asking exactly that. Basically the answer you'll get is, anythings possible, but no you do NOT want to do that. The engines are not as similar as people think they are, and the first gen durangos actually have a pretty complex wiring system. A lot of the interior wiring runs off of a two wire BUS connection and there's just really no good way of doing that swap. Would be easier to swap a 5.9 (360) from the same year into it. And even then You would have to swap the harness, ecm, and ctm from the donor vehicle. Then you may still after that have problems. Not to mention the 5.9 won't bolt to the 545rfe (assuming that's the trans you have?) so you would have to swap a 46RE into it as well. It's a nightmare, not recommended. Also, 2004 was the first run for 5.7s in durangos and I think they may have put them in trucks in mid 2003 but either way, early 5.7s (2004 included) are known to throw rods. So ya don't really want one anyway.