Do I need a new head ?

[Hammerhead]

I'm not familiar with the DD13 heads, so I DO NOT know what they look like new...
But holy shi#t batman!!! Do those valves look severely recessed into the head/seats!
With 550k miles, yes I would change the head. It's off anyway to replace that valve. I don't know about DD's turbos and/or actuators.

edit to add: actually taking a closer look at the picture I see that DD recesses the valve seats into the head, but I would still advise a new or reman head since it's off anyway. The only way I'd say to reuse this head is if you are going to patch it and sell it if you're not concerned about your used equipment reputation if it fails shortly and becomes known.