I towed a Case 480E backhoe/loader from Montrose, CO to NJ with my then 1986 6.9 F250 Super Cab 4x2 with a four speed manual trans. The trailer was a late 60's construction equipment trailer that had more patches and diamond plate on it then it had original steel. The truck belonged to the guy I worked for at the time, he had bought it new the year before. He paid me to drive it out to CO to pickup the Case after a relative of his passed away out there. All I was told was that its a backhoe, and the trailer is good, 'he used it all the time'. He handed me an envelope full of cash for expenses and the keys to his new truck.
Once I got out out of the hills it wasn't that bad, but on the hills, The truck did fine, I just took my time and wasn't in any hurry, (After all I was getting paid by the hour). Not long after that trip, that truck become my personal ride. I don't think the boss thought much of the smell of diesel because a year later I bought that truck off him after he decided to buy a 1 ton in '87 with a 460 and an E40D. It was probably the best $5,500 I ever spent. Its a truck I really wish I had kept pver the years.
Looking back, with a few more years under me know and a bit more sense, the trailer was likely close to 4,500lbs empty, the Case was probably around 12,000. The Super Cab long bed diesel truck with a fiber glass cap on it was likely close to 7k plus an array of tools, chains, etc. in the back. I also had four new trailer spares and a couple spare hubs just in case. I took I-80w going out, and I-70E on the way home. It took me about 33 hours out and 44 hours drive time to get home towing the Case. As far as i could tell the truck was no worse for wear after that trip, but it was a fairly new truck at the time, (still under warranty when I left). It clicked off 12k on the odometer about 10 miles from home on the way back. I took my time, took time to stop and rest and all was fine.
It was likely a bit overloaded but it did the job. When I first pulled out with that trailer on the back my first impression was that I was likely going to hurt the truck if I hit any big hills, but after the first two big climbs and a couple long winding downhill runs getting out to I-70 to head home, I felt more confident it was going to be just fine so long as I took it easy. I ran 50-55 on the open road no problem, but took it super easy getting up to speed and planned my stops well ahead of time.
I think that truck felt more comfortable towing that Case home than my current 6.0L Power Stroke feels towing the same weight. The difference is that the 6.0 does it faster and gets better mileage doing it.
The 6.9 got around 8 mpg hauling that Case back then but it got closer to 15 on the way out there. It went through about 400 gallons of diesel both ways, but diesel was cheap then, between $.69 and $.73/gal. I think I spent around $280 in fuel for the trip. I was only making about $5.25 an hour then but I didn't have to pay for food either. I did sleep a few nights in the truck, but only because I didn't feel like finding a motel, I also drove mostly at night to not have to deal with traffic.