I got a head off a 1980 truck to work on getting my efi setup to fit and do some port matching/ clean up/ etc. while my motor is still together and running. Will that head have hardened exhaust seats from the factory for sure? Do they last or are they very shallow?

If it's a peanut plug head it will have hardened seats...
So far as I've seen if they do a valve regrind you are gambling, if this is a Hipo engine with O/S vavles you are going to have the machinist install new ones.

-D.Idiot

If you’re considering oversized valves, my machinist told me chances were good when seat is cut larger he would be into non hardened material. I had him install larger hardened seats; I think that was a $6 per valve additional charge four years ago.

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67' Dart GT Convertible; the old Chrysler Corp.
82' LeBaron Convertible; the new Chrysler Corp
07' 300 C AWD; Now by Fiat, the old new Chrysler LLC