Swapping diesel set up into my pickup up truck?

Will need the fuel tank also if I am not mistakenalong with the fuel pump setup since if I am not mistaken but the pressures are a lot different, also need the exhaust. Make sure the mounts are the same. You will need to make sure the diesel engine has some sort of vacuum pump or source for yours if yours does not have hydroboost setup. You will need vacuum for your brake booster. Since diesel engines do not create vacuum, you will need an external vacuum pump & all the plumbing for it so you have power brakes

If you have a donor truck it should be relatively easy. You will needs the mounts in addition to the stuff you listed. Swapping to a diesel is kind of pointless on a half ton though, you will overload the truck before you run out of power with the 350. I towed a 13k trailer with my 91 GMC 1500 with a 350, and the truck was so overloaded.

If you need more power you could swap the axle to a 12 or 14 bolt with 4.10 gears (you can do 4.10 with the 10 bolt but it wont last).

You shouldn't have much difficulty. Those older Chevy Diesels were basically just a gas engine converted to diesel and not much else was changed as far as transmission.