Might be in the market for a Dodge Cummins 5-Speed?
 

Hello DB! My name is Anthony, and I have been working 13 hour or so long days crawling up in attics doing insulation. Right now me and my partner are using my 1974 Ford F-250 Super-Cab which has a built 390ci V8 FE with a mild cam. (I bought this truck because I already have one, and I wanted a Super-Cab, and it doesn't need to be smogged in CA)
Well anyways we cannot afford the gas in my truck, so I was thinking of getting a Dodge Cummins, because we will get much better mileage, and yes I am aware of the high costs of maintaining a Diesel. But our fuel savings will cover any of that. I've had friends who have a Cummins before and they are great trucks. I will be saving my money up for this Cummins for a couple months, and I will sell the F-250 to help fund the purchase. We've had Diesels, but never a Cummins.
How much should I set aside for a budget? About 4-5K?
I would like a mid '90s Dodge Cummins 2500 2WD 5-Speed 5.9 Extended Cab, that would be my dream truck.
What should I look for? Anything I should know about these particular Cummins?
Is the 6-Speed manual better than say the 5-Speed?
How much many miles could I put on this truck, and how often would it have to be serviced? Our jobs require long distance driving, which is one reason I need a Diesel.
Could you get these trucks with dual tanks?
Is the setup I am looking for hard to come by?
What kind of maintenance has to be done, and what does that usually cost?
One of our Diesel had injectors that were spraying too much and causing bad fuel economy. They were very expensive to replace.
What would you guys recommend? Thanks in advance!

Good Luck!