I'm at the beginning stages of diagnosing but it appears I have either a bad head gasket and/or head work that needs to be done, so I am starting to source my options. I had a thermostat stuck close in 2018 and a Mitsu dealer said they milled the head but they have no record of how much, so I don't know if I can still use my cylinder head again.

1. Does anyone have the specs I would need to provide to a machine shop that can measure my current cylinder head to know if I am still ok to send it off to be surfaced and rebuilt?
2. Any recommendations for shops to do head milling and restore work? I have found MAPerformance and English racing as options thus far.
3. Anyone recommend a place to source a cylinder head core if I need one.
Thanks!

 

I don't have the specs but my local shop had them and was able to check it over for me.
As for a core, likely going to need to hit up a facebook group or a junkyard. Given that you have an 8, there is also the Hyundai head option. You should have an easier time than us 9 guys.