I have the Hemi with the 8-speed and 3.21 rear. It will pull 22~24 mpg on the hwy and is the first truck I've ever driven that doesn't drastically use more fuel when you bump it up to 80 or so. The V6's are getting about 2 mpg better.
Now Equip an Astro with true 4WD hi/lo Tcase, and a 3.0L turbo diesel, and you do have an ultimate utilitarian vehicle.