2-Ton
I have had Detroit Diesel people tell me that the 8.2 should be good for about 300,000 miles if it is taken care of, and like I said, I have not had a lot of problems with them. They are a dirty engine though, and I think that is what killed them.
I have had the best luck going to a Detroit Diesel store for parts and information. Regular parts stores in my area don't have to much for them. Stewart Stevenson is a large Detroit Diesel distributor, and has a store in Denver. I don't know if they would have one close to you or not. If you find a Ford truck or Chevrolet or GMC truck dealer, they may be able to help you, since both used that engine. You will need to go to a truck dealer that has the commercial lines, not just the car lines.
The ID tags should be stickers on your valve covers, that will give you information as well as the settings for the injector heights if you tune it up.
Good luck
Jim