Uleaded fuel or not

[khnaess]

Hello!
So I got a 1972 f250(produced in march 72) with a 390 engine and c8ae-h heads. Do these heads have hardened seats for unleaded fuel? I did not expect to find this heads on my truck, I thought they used the D2-Aa heads(with hardened seats) from 1972...

[markguiver]

The C8 heads may have had hardened seats installed at some point in their life. I had the C8 heads rebuilt for my engine with hardened valve seats after one sucked a valve about 18 years ago. After almost 50 years it's hard to say what's been done to them.
Mark.

[basketcase0302]

Even with the hardened seats the issue I've always had with unleaded fuels was detonation. I couldn't run unleaded, (even premium) without detonation and dieseling which is a quick death to an old engine. Recreation boat I had, (running the only chebby engine I ever owned) was a 454 pushing 375 HP that I had to run premium unleaded back when the cost of ethanol free went over $5.00 a gallon in Florida.
The only way I could stop detonation, (which can be deadly on an airboat) was to install a fuel solenoid on the 750 Holley which slams the throttle plate shut on loss of power.
Not trying to take away from your concern of hardened valve seats but also pay attention to any and all dieseling symptoms using lower grade ethanol unleaded fuels.

[khnaess]

Ok, thanks. I guess I just add some lead additive
now and then, just to be sure.

[basketcase0302]

That's exactly what I did. I haven't bought any in some time now and do remember is becoming harder to find with the "sky is falling" (greenhouse gases / emissions) world we live in.