Cool swap! I've done two diesel swaps into the old square body trucks myself: a 1977 K5 Blazer and a 1981 C20 truck.
First off, for simplicity's sake, I would recommend swapping the engine only and converting it to a mechanical fuel injection pump. The 1995 model is equipped with an electronic DS4 injection pump that is problematic and requires a computer for the engine to run. You would have to swap the computer and complete wiring harness in order to make the engine run in its current configuration. However, a mechanical DB2 pump, such as used on 1993 and older engines, will be a direct bolt-on. You will need the injection pump and injection lines. This only requires one wire for operation. You will also need a throttle cable, since the original engine is drive-by-wire. Swap everything else from the engine compartment, including serpentine drive system and components, radiator, hydroboost brake system (since the diesel does not provide vacuum for the current gasoline engine equipped brake booster).
I would also recommend using your existing 350 tranny and transfer case. Again, the transmission in the 1995 is computer controlled, and would be a hassle to make operate in the older truck. Also, the transfer case in the 1995 will have a driver's side output for the front shaft, whereas your K10 has a passenger side output.
Casey
1995 K1500 Tahoe 2 door, 6.5LTD, 4L80E, NP241, 3.42's, 285/75R16 BFG K02's; 1997 506 block; Kennedy OPS harness, gauges, Quick Heat plugs, and TD-Max chip; Dtech FSD on FSD Cooler; vacuum pump deleted, HX35 turbo, Turbo Master, 3.5" Kennedy exhaust, F code intake; dual t/stats, HO water pump, Champion radiator; Racor fuel filter