I am looking at buying a 1984 F250 ext cab 4x4 with the 6.9idi NA and a 4spd trans. The truck has around 130k miles and a descent body. I was just wondering if any one could give me some advice on what to look for as far as potential issues or what I might want to do after I buy it. It does have some issues (brakes, tires, etc) but the price is right, the 4 wheel drive works and it does run well. I have owned a couple of diesels in the past (a Mercedes 300sd and a 94 6.5 paperweight) but never really drove them. I know the 6.9s are a very durable motor other than the small head bolts and the head gaskets, but should I have anything else to be concerned about? Also the same guy has a 2wd auto the same year with an aftermarket turbo kit. I may be able to get a package deal for both and was considering swapping the turbo on to the 4x4. Would that be worth my time or would I be better off leaving the 4x4 stock? Any advice would be appreciated and thanks in advance.