Looking around I find a lot more 3500 diesels than 2500.

Price difference is not all that great. About 400-500 on a similar truck.

I didn't buy a dodge this time but I bought a Ford F350 because just like you mentioned the price difference isn't squat but the payload can be huge. Both are equally rough to ride in but the 1 ton can help you stay under the legal tow weight combination weights. If you buy a 1 ton just make sure it has the same rear axle ratio as the 3/4 for decent fuel mileage, unless your are going to be pulling big heavy trailers, then get the higher axle ratio.

I think in the 2000's it was mainly the springs. One more leaf in the back.

The Dana 80 was in the 2wd 2500 and 3500. The 4X4 was a Dana 70 if I remember right.

The tow ratings of the two trucks were not very different. A couple hundred pounds if I remember, with the single rear wheels anyway.

So I'd be looking at pretty close to the same mileage with either truck.

If you get the same rear axle ratio then the mileage will be exactly the same.

Thanks. Seems that they come with the same axle if they both have the diesel.

are you talking new or a specific used model year? Also, are you talking 3500 single rear wheel or dually?
If you are talking new, there are several differnet versions of the cummins powered trucks. If you get the Aisin, you get more power and a different rear axle.

New, single axle.

I bought a 1-ton srw in 2010 because it was $1000 dollars less than a 2500. There is less demand for the 1-tons. It will also cost you more to register the 1-ton.

1-tons have cab lights, most 2500's don't. Oh and the leaf springs.

You can get 1-ton srw's without cab/marker lights.

Yep, they are actually becoming rare to have them. My f350 doesn't have them.

I got my 1-ton without them because Ive seen too many trucks with busted out marker lights rusting up a storm. That and I don't need any more bulbs to check/replace.

2500 have 3.73 gears and 3500 have 4.10 gears. better for towing. most 3500 are dually style. they also have a bit higher tq and hp.

That's not really true. Not all 1-tons come with a higher rear end and typically they all have the same motor. Dodge offers a lot more options now than they used to, but in the past you got the same motor and trans in both.