Between years 2000 and 2017?
I want to make a reasonable decision for longevity of a diesel engine in a HD truck that will be used for either a truck camper or perhaps a trailer before I purchase next year.

Pro's and con's of each of the big 3? (Chevy, Ford, Dodge)

The Cummins is superior. Especially in the 2004.5-2007 Trucks. Sadly, they put them in Dodges, so the rest of the truck will fall apart around that Cummins.

12/24v Cummins. Hands down.

I agree with the above statement. Cummins all the way. Bullet proof engines, well not literally...

I'd agree, when I bought my Ford F-250, what I really wanted was a Dodge (well, what I really wanted Toyota doesn't import into this country) with a Cummins. That said, I've had very few problems with my 7.3 liter International Harvester in my F-250 other than crappy mileage and an fuel oil pump.

I wouldn't buy one again, but not because of the engine, the truck itself is not very well made, things have stopped working (passenger side door lock, center console mileage, compass, etc.), light lenses have fallen off on the passenger door (which gets used far less than the driver's side). That said, it's a towing machine, it happily towed my 6000 lb + boat & trailer over Mt. Hood at 70+ mph (didn't mean to be going so fast, and actually thought I'd lost my trailer when I realized how fast I was going).

Resale tells the tale. The 5.9 cummins seems to be one of the lowest maintenance longest running engines. Dodge trucks will eat transmissions though.

Yeah theres got to be an issue with the aluminum headed diesels sooner or later...it just goes against nature.

High compression, combustion pressures and fuel detonation eventually has to knock the shit out of them.

The guy we bought our boat from in Bend, OR ran a shipping company towing airplane parts cross country. He owned a fleet of Dodges, but the ones he wanted to sell, he warned us away from since they had well over a quarter million miles on them, they were all duellies, most were not 4x4 which I definitely wanted, and all were kind of beat up in the way you'd expect someone who didn't own it would treat it.

7

Supposedly most that was fixed in 04. I have an 06. So its the 24v Cummins. Best damn diesel out there imho. Except for maybe the 12v. Dodge trucks have come a long way since the 80s and 90s. However, if you want a plush ride on a couch, buy Chevy. Want real truck with real HD suspension that rides a bit harder, buy a dodge.

I am still thinking about trying to combine the best engine/transmission with the best pickup body and interior.
Has anyone heard of the good Cummins being adapted to a better pickup?
My favorite pickup in the modern age (post 1970ish) is the early 1990's Chev.

Is the dream impossibru?

People put cummins engines in every thing. Look up cummins charger on YouTube. When my truck finishes falling apart I will put it in something old. Wait, on second thought don't buy a Dodge, it's an addiction. The quest for more power never ends once you start. Hi my name is Eric, and I have a problem....

Sound diesel performance in Auburn does Cummins swaps. Have no experience with them, but was looking into the same thing a while ago and found them.

Anyone have a Ford 6.7?

In all seriousness, take the engine out of the equation and compare body and interior.
Having to work on Ford and Chevy's all day long with a random dodge tossed into the mix, I'll take a Ford truck any day if I'm soley comparing suspension and interior, holy fuck do I hate the dodge and Chevy built to fall off and keep the mechanics employed idea...... I like to be able to lean on my armrest, not have the turn signal assembly fall out, cracking frames etc etc. Doing this all day long on the major 3 has brought a bit of resentment and hatred towards the engineers of the terrible two.

Now, look at engines. Older Chev 6.6 engines where pretty damn good, except for the fuel injection on exhaust stroke to clean exhaust system which wears out rings and makes you short fill on oil changes because it's going to grow.
Cummin's...... while not much negative, not much super spectacular either. Want more HP? Open wallet, repeat..Emissions cost is hurting after warranty over.
And Ford, I love the Ford 6.0 and it cannot be argued the easiest way to hp by all stretches, but unless you are super anal about servicing, know what to do and watching the go pedal, not for most folk and will give you heartburn. Toss in Ford 6.4 that made gobs of HP, but longevity sucked unless some knowledge an bypassing EPA very early in its life, an now we're into the 6.7, holy shit is it everything all the others aren't.

Yes, have had a couple 7.3's a 6.0 which was my favorite cheap ride and abused the hell out of her but maintained an fixed before problems came up. Now onto a 6.7. When combined with a sturdy vehicle, the 6.7 is a nice smooth and quiet ride, with shitty fuel mileage....

So....Dodge is the Cummins only? I see a 6 cylinder diesel out there now in trucks? What's the story on it?

Also, as I tell others that ask, unless you're towing heavy and often, a diesel is a waste of your money.
If you're throwing on a mid sized camper or a tongue trailer and only towing maybe a dozen times a year, you'll save money in short an long term going gas.
Now once you get into a huge double slide camper that sticks out 6' or some heavy trailer or fifth wheel, or tow a shit ton, then yes a diesel will fit the bill.
Regardless, a diesel is more to maintain, and more expensive to maintain.