Can/should you re-use engine components?

The cam thrust plate should have a hollow bolt with a small hole in it in the top left position. Also the oil drip plate.

The Hollow bolt works, I've checked chain stretch on 340's with 100,000 miles on them. The stretch was still within specs. I would not run the hollow bolt and the oiling tab together. I have only seen the tab on later engines. As for the original question, If your parts are still within spec, I would not hesitate to use them. Lots of new parts are not up to the standards we used to expect.