I am looking at an absolutely mint 1985 regular cab chev with a diesel. 2500 4x4. 45000 original miles. truck is flawless. is it worth $6,000? are there any mods availible for this truck that wont alter it too much? what can you tell me about the motors from this era? what motors came in these trucks? what is the best? can i put on a turbo. it has an auto tranny. i dunno much about these any help would be appreciated!!!
Thanks.  

and also how easy are these to work on. what are there weak spots and strong points.  

i have an 85 K5 and they are decent trucks but sluggish as hell, i would also want to run a bypass filter on it because the stock paper filters aren't that great as far as servicability theyy're a whole lot easier to work on than any newer truck it just takes one hot wire to the pump and thats it but i still thinkits eiasier to work on an old IDI ford or non electronic controlled cummins ( because you have to take the intake manifold off to get to the pump and the injectors can be hard to reach). as far as power you can turn the IP screw a 1/4 turn clockwise to run more fuel and slide the pump to the right a hair to run a lil more timing but thats about it and banks used to make a turbo kit for it.