I usually think a decent deal on used parts is 50 cents on the dollar. Used engine parts even less. I look at how much I spent on my engine and think I'd be lucky to get 25 cents on the dollar. If the stuff is that old it's out dated and some parts like turbos can cost more to repair then to by new. So with that risk. I'd say that they are not worh much. Maybe 3k each. Good Luck.