Best 5.7 to Dart

I think you hit on the main question there, car vs. truck engine. You can swap covers between the two, so really it's not too big a deal. Really whatever you can get for the right price will probably be your best bet. Along with the water pipe differences the accessories mount in different locations as well and are not swappable between the two, so that's something you may want to consider. If you swap the cover all the accessories will have to go with it. I think the truck engine is generally considered more of a drop in than the car because of clearances issues with some of the accessories, but the car engine is generally preferred for looks because it tucks things away nicer.