I have a '73 head from a van. I know it has "induction hardened exhaust seats" (as per DD). I'm having a basic 3 angle job done (with new valves) and the guy said that he doesn't think it has them (he also didn't think I had adjustable rockers). Of course I will take Doug's word as truth.
My question is does the valve job compromise the hardened seats at all? I am having the .060 mill done also. Should I have hardened seats installed? I don't think so but I want to be sure. I'm doing a 252 Comp cam with 4bbl. He said running super unleaded would help.
Any thoughts?

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"Nothing in all creation is hidden from God's sight. Everything is uncovered and laid bare before the eyes of Him to whom we must give account."

Induction hardening is just a surface heat treatment on the cast iron and it is not that deep. A valve grind can cut thru the hardness.
You really should have the hardened seat inserts installed on all the exhaust valves to ensure long life on unleaded fuel. ( the intake valves don't need harden seats)
DD

Thanks for the reply.
On one hand , I didn't think I needed them 'cause I only put about 2000 miles on it a year.
On the other hand, it's only another $100 and the engine is apart.
I think I'll do it.

_________________
"Nothing in all creation is hidden from God's sight. Everything is uncovered and laid bare before the eyes of Him to whom we must give account."