By this do you mean just the 7.3 Powerstroke and not the 7.3 Intl.?What do you mean by "naturally aspirated" ? Is that just the 7.3 without the Turbo?

I seen a 5.9 Cummins 1993 Dodge for sale...are those good engines/trucks?

What years were the 5.9 Cummins made?

Do they have Turbo and non-Turbo versions of the 5.9 Cummins, like Ford and GMC?

Reminder: I have NEVER owned a diesel and I don't really know much about them.... which are duds and which are the better trucks with good powerhouses.

You don't need a one ton diesel to pull a 2H BP trailer.

Buy any one of the big three gassers in a 3/4 ton rating, with their largest gas engine if you're worried about the power. They're less expensive to buy and maintain, and there are thousands available country wide.

Gard

The 7.3 liter engine in the Fords was built by International. It first came out in trucks and vans as a naturally aspirated engine(no turbo). That engine is a good engine , and you can get a lot of miles out of it, but it lacks power and it will smoke. Then came the 7.3 Turbocharged version. Better, but not as good as the Powerstroke version. I think the Powerstroke was introduced in 94 or 95. I was working at a Ford place then, but I don't remember for sure which year. The 99 Superduty came out in late 97(wierd, huh) and it was a lot more user freindly truck than the 95 to 97s. More HP, better gearing, quieter in the cab(nothing like today's diesels, though). If I were buying an older Ford diesel, I'd be looking for a 99 to 2002 or 03 7.3.

As far as the 5.9- I don't think Dodge ever put a non turbo version in their truck. The older 5.9 in the Dodge is a great engine. A little short on the horsepower when you compare it to the engines in 99, 2000, 2001 pickups, but when you compare it to the gas engines of the day, it was a real step up. The older ones also get good mileage. My stepdaughter has 94 3/4 ton Dodge 5.9 diesel that she pulls a 4 horse Hart with. I'll out pull her on the hills with a 2000 Ford with the same load, but on a 100 mile trip there won't be 5 minutes difference in total travel time.  

90% of the 6.5L diesel with the SEL is a bad fuel cap!

The problem you are having with it stopping and then being able to restart is going to be the little black module that is mounted on the side or beside the injector pump!  This has been biggest problem GM had with the 6.5 diesel.  Look up heathdiesel.com they have a easy relocation fix for this problem.

If you are wanting a stout ol' work horse the 7.3L IDI (non powerstroke diesel) would be the weay to go.  Sure they are a little less hp, but they are REALLY CHEAP to work on and does not take much to keep them running.  And you could find one of them cheaper priced than a POWERSTROKE.

Yes, the 5.9L Cummins is must likely the BEST diesel built, however some of the Dodge bodies did not last as well as the engines did.

Dodge used the 5.9L Cummins from 1989 to early model 2007, they had a GREAT 12 Valve engine from 1989 to 1998, then in 1998.5 the cam out with a 24 valve engine more power and electronic injector pump. 

Dodge only had TURBO engines, the early models did not have an intercooler!

Last but no least, my opinion you would have to flip a quarter then pick the Ford or Dodge, both had good and bad issues, both are really simple engines, the "powerstroke" will cost a bit more to work on.... 

ie: 5.9L injectors $200 to $500 per set, Ford IDI engine injectors $90. to $175. per set, Powerstroke injectors about $900. per set.

Sorry to be so long, but if you are looking you need to know up front!