Is it 350 for just the engine or teh whole parts truck? I wouldn't spend too much ona non runner, but I bet you could part it out and make a lot more than you paid for it provided its under 1000 bucks. A knocking engine I would look at as a core. It may have a simple problem like glow plug tips in the cylinder(still ahve to pull the ehads) a bad injector, or advanced timing, or it might have a bad crank or spun bearing. Your gamble, but I know what YOU really want is teh heas most likely. I'd say 200-400 bucks for it is fair. Tranny? a good C6 diesel 4X4, maybe $500-800? maybe a lot less, all depends on if somebod needs it. The axles could be worth something to teh right person especially if they are 3.55 or something higher than 4.10s. Fuel economy is a big issue these days. Fuel system... filter headers are dime a dozen, water separator is a negative item, injector pump? aghain its a core, but the lines are nice to have, and you might get lucky and its good. All in all, I'd pay $500-1000 for a truck like that and hope I got what I wanted out of it. I'd hope for a better deal from someone who just wanted it gone though.