Diesels are expensive for what you're wanting to do. It's the little things that eat you up with a diesel on a regular basis. Injectors, turbo, pumps, etc. All of these little fixes can be thousands of dollars. Or, you buy an old 7.3 with 200k and the engine totally gives out and the thing is basically totaled. Like others have mentioned, I'd find a nice Ford V10, 454 big block chevy gasser, or a Dodge V8 or V10. Gas is so nice; they start when it's cold without being plugged in or having glow plugs, etc. They don't need to be warmed up for 20 minutes in the winter. They aren't loud and heavy. If they blow up, it's a couple grand to pop a brand new engine in them. At the weights you're talking, on flat ground, gas is a good way to go. No one wants these bigger gas trucks anymore due to the simple fact that they are not fuel efficient for any projects other than the narrow spectrum of work which you have found yourself in. Fewer and fewer people are farming or working on a small scale. For most small stuff, an F150 works. For big stuff, you want a diesel. So, because of this narrow range of weight you are working in, you can pick up a nice 250/350 gasser with 100k on it for dirt cheap and if you maintain it and go easy on it it'll probably run for 40k more without an overhaul. That's my two cents anyway. When I started out I bought a 94 dodge cummins with 205k to do what you're talking about doing. I got lucky and it ran great and never really let me down... but the starter failed and that was $600... and it leaked oil everywhere and to fix it would have been a heck of a job... and it was so loud I wanted to wear ear plugs when the windows were down... I am shying away from diesels now. I run a Volvo road tractor to haul heavy loads and use gas V10s for route trucks. The Ford V10 has been a good engine for me. Cheap to fix, cheap to maintain, doesn't complain, few issues... plenty of power for 8000lbs towing... late 90s Ford V10s are solid machines... Just my thoughts.... good luck
