Adding Lead to Gas

If the valve seats were replaced, great. If not, there probably is enough parasitic lead on the old ones to lube you a good long while. If you worry at night about it, throw in a bottle of lead.

65Mustang2+2 said:

Hello Mustangers,
I have a question about adding lead to my gas. When I bought my car the guy told me that I need to add a lead additive to my gas when I fill up!
Do I really need to do this, or is it just over kill. I don’t drive the car that much it stays locked up in the garage most of the time, it’s not my daily driver, it's just a weekend cruiser. I dont know if harden vales seals where used?

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If it's only occasional use, then I'd not worry too much. But when you have a little extra money and time (like over the winter), pull the heads and have hardened seats installed and you'll never have to worry about it again.

What kind of engine do you have anyway? When was it rebuilt? Was it rebuilt?

I wouldn't lose any sleep over it. I rebuilt my 260 V8 20 years ago and, at the time, opted not to have hardened seat valves installed on my heads. I should have done it, but funds were tight at the time. Anyway, when leaded fuel was finally phased out in 1986, I started using lead substitutes and that "Real Lead" stuff when I could find it. I discontinued using the additives after a couple of years because I thought they were "gumming up" my carb. I have not added anything to the gas since. I have not pulled the heads, but I have not had a problem with the engine yet. My car is just a weekend cruiser and I drive it at most 2,000 miles per year. For a weekend driver, I wouldn't worry too much.

I think that heads manufactured from 1972(?) and up had hardened seats. If your heads have been replaced with 72 or newer heads, you might not have any issues at all. Also, as already stated in the previous posts, you could always throw a bottle of that leaded mix into the tank from time to time as insurance.

Out of subject.

I run 110 leaded gas on my 89 check sig with a mix of 91 unleaded and hmmmm it smells way better than conventional gas burning.

I try to put a bottle of lead additive in my 67 every two (but usually ends up being every three or four) fill-ups. Did the same with my first 67, which also had a 289. No problems.

I wonder how many folks have had the heads rebuilt by a PO and they just don't know it. Most of these engines have been rebuilt a time or two, and it would only make sense that the heads were done as well.