Hope you don't mind me butting in...........but I'm starting a build on a new 2011 Ram 5500 as well so I thought I'd toss in my two cents as to why I chose the Dodge over the Ford. My main reason is under the hood, I love the Cummins. It's reliable, stone axe simple and easy to work on and get to things in the engine compartment. If one were inclined to remove the EGR, EGR cooler, DPF etc...it can be done in the driveway with simple hand tools. I've overhauled two of the 5.9's and was impressed with the robust build and simplicity.
If you open the hood on a Ford, it's hard to even find the engine. In fact, for any major work the cab is lifted off of the frame. Also, IMHO, a truck turbo diesel should just be a straight six.
I have to say though, that until the 2010 body change, I was jealous of both my brothers Ford Lariat interiors, now though, I think I like the Dodge just as well if not better.
IMHO, the one thing the Ford has going for it is the availability of a front locker. But, I think Dodge has the better overall front axle. (massive hi-pinion Magna-Steyr).
I'm not trying to start a brand p*ssing match, I'm just giving you my reasons for choosing a Dodge for this application. I did own an F550 a while back, but I missed my Cummins . :ylsmoke: