I had a 1995 F350 crew cab 4x4 PSD 5spd. I really liked the truck, but the last 40k miles I owned it, the repairs ended up being equal to the payment on a new truck, so I traded it and bought new. Everything up to 200k miles was pretty basic maintenance, it was 200-240k that got me.
I agree with the comment about a spare CPS in the glovebox, and keep a 6pt 10mm wrench in there too.
Glow plugs, glow plug wiring harness ( it is built into the valve cover gasket), glow plug relay (Napa GPR109 if I recall correctly) are all pretty common issues, none of which are very expensive.
If it has a 5spd, the factory dual mass flywheel is a poor design, you will end up upgrading to a LUK 13" clutch assembly.