Go to dakota durango forum under the 5.7 hemi section.
Look for FrenicX post.
He did a 2005 4.7 to 5.7 swap.
Used the 4.7 ecm with a tune.
HP tuners has the ability to tune said ecms from 04 and up.
If you use the stock ecm you cam keep all the bells and Whissels with no check engine light.
Matt