Mike, you need to check your source - they're no good! Ford sold their shares of Cummins about 10 years ago, and now owns none of Cummins. There have been rumors galore about a MB diesel in Dodge, but Cummins has a contract to 2007.
As for the diesels, like GravelRat said, if you want a true crew cab, you pretty much have to look at Ford or GM, especially in older ones. As for which is better, that's a topic of hot debate (right Gravel?
) I presonally prefer the straight 6 Cummins over the more complicated V8 Powerstrokes, and would be willing to sacrifice a little on the cab for the engine - although for me the Dodge isn't a sacrifice. The 1st gen Dodges, 89 - 93 are the lowest in power, but the easiest to upgrade - within limits. The '94 to '97 got progressively stronger, with the manuals having more ponies than the autos. Again, these engines are very easy to modify (for more HP and more mileage), and the liimits are much greater than the 1st gens. They also have the more reliable mechanical fuel pump, but suffer from Killer Dowel Pin syndrome. There's an assembly dowel pin at the front of the engine that has been know to make its way loose upon occasion. That is fairly rare and there is a fix for it. The '98 (mid year) - 2002 are great trucks, with nearly unlimited horsepower potential. However, they are prone to trouble with the fuel pump. As for 4X4, none of them are trouble prone, and of course the manuals are better for pulling than the autos.
As for mileage, the 1st gens seem to run in the low to mid 20's, the 2nd gen (94 - 97) seem to run just a tick lower, and the 3rd gen (98 - 02) are a little lower still, and not quite as dependable in mileage from truck to truck. I managed to get around 19mpg on mine, with oversized tires up to 160,000 miles when I traded it off.
With either a Ford, Dodge or Chevy for that matter, you'll get a truck that will work great from you. I will say I'd trust a high mileage Cummins more than the other 2 though.
Good luck.
Randy
