The older Ford diesel's have a solid reputation (not the 6.L newer junk) and my 1989 F250 4x4 is still runing reliably. Not sure which year they stopped making it and switched to the newer engine which is the subject of a multi-million law suit with International.
Just wanted to add this. Back in 1992, I needed a good used pickup truck to haul with (not as an everyday vehicle). My trusted auto mechanic went to the auctions for me for several weeks until he found a truck that would fit the bill and my budget. I was the proud owner/driver of a 1986 Chevy one-ton 4X4 pickup, single cab, long bed, 454 engine (gas-hog!). I drove that truck every weekend for 10 years, and sold it for not much less than I paid for it. The folks that bought it are still using it as a farm truck to do plowing, etc.
There are friends and faces that may be forgotten, but there are horses that never will be. - Andy Adams
Not sure what you mean by older? We've got a v8 2002 Ford F350 1-ton (last year before that crappy new engine) that we really love. We've also got 2002 Chevy 2500 3/4 ton that I don't like as much. Could just be that the Ford is a nicer package (leather, heated seats, etc) and bigger so it just feels more solid. I tow our steel 2-horse slant with the Chevy only when I can't have the Ford because the hubby is off hunting/fishing.
ETA: There's a long story behind why we have two big trucks. Suffice it to say that the Ford is our "nice" truck and it's pretty much driven on weekends and to pull the trailer or boat. The Chevy is my husband's work truck (contractor) and is his daily driver.
SO MUCH depends on how the vehicle was maintained. There will be personal brand preferences of course, but no matter what it is, if someone didn't take care of it, it won't last. Look for rust underneath, coolant/oil leaks, condition of hoses/wires/connectors under the hood, maintenance records.
One where the guy did his PM's and has the records to prove it.
This x2000000. You want the maintenance records (even if the guy did it himself, he should still have receipts.....I do most of my own work on a vehicle I'm never planning to sell, and I save everything) and you want a truck that hasn't been plowed with. Plowing puts A LOT of strain on EVERY part of the truck....so you just don't even want to go there.
You also want to stay away from anything that's been teenaged-boy owned. 'Cause it won't have been treated nicely, trust me. Same with off-roading trucks, even if they're adult-owned.
Myself, I'd argue that you can't beat a Chevy 350, no matter what the year. I have a 1976 that fires right up, even after sitting for years. It's a good engine. But even they can only take so much if they've been consistently beat on.