I would replace the guide plates of course. I have never seen one crack or break.
The lifter will only pass
oil in certain positions. If the
oil band on the lifter is not in the path of flow, it will be less likely to pass it up through to the pushrod. Roll the engine over and you should be able to get
oil out of all 16.
If things got that hot, you would see a lot of bluing on the parts.