Good luck. Seriously. In over 30 yrs I've owned 1 non-Ford truck (it was purty, but a turd under the hood) and in all that time I've come across exactly 1 service dept I thought had their s**t together.
If I had any advice to offer it would be to look for a small dealership, with a small service dept. They're more likely to have it together. Generally the bigger depts turn into get it in, get it out, assembly lines with turnover being the name of the game. Shotgun trouble-shooting is way too common in these types.
The one I found was in a po-dunk little town and I believe the top thing that made their service dept sound was that the service manager himself knew his stuff, and wasn't just a people manager. I could always deal with him directly and he never steered me wrong or let me down.
I appreciate everyones input. Greg sent me to a shop whose fleet manager and diesel mechanics seem very good (Five Star Ford in Lewisville). I'll be using them and will post my experiences as time goes on.