Dodge V10 or Cummins?

[mopar1]

My current truck is both too old and not GVW rated to pull my new Montana so I am looking for a replacement.
At this time I have found two trucks I can somewhat afford. One is a 95 Dodge extended cab 2x4 1ton with a V10 and a 97 4x4 everything else the same Cummins.
The V10 I have not seen yet but it looks like it is in good shape with 100,000 miles on it. He wants $5,500 obo so maybe I could get it for $4000. The 1997 Cummins truck I looked at today has been neglected. It has 106,000 miles. It needs a lot of work. It needs new front tires, the doors are rusted out, the front of the bed has been pushed into the back of the cab, the seat is ripped on the side. The paint is cracked off and rusting in places. He wanted $10,000 for it but I talked him down to $8,000 even before I went out there because that is all I have to spend. I cant afford to do any work on it with that price tag.
I will not use the truck often as we will be leaving it in the camp ground through the summer. We do plan on taking it on a vacation maybe a couple times a year. Maybe 1 or 2 thousand miles a year with the camper.
So I consider the costs of the trucks and the price of fuel and wonder is it really worth the extra cost for a diesel truck or should I keep on looking for a better diesel and pass on the 8-10mpg of the V10?