Somebody told me that unleaded gas burns hotter than leaded gas. If this is true is it ok to use a lead additive if your heads have been changed to the harden valve seats?

What I understand from talking to various people, if your engine has had a valve job in recent years you most likely don't have to worry about using unleaded gas because the parts and pieces that were used to rebuild the beast can handle the un-juice. But you best know what went into the rebuild, original new parts or current new parts. That's the only way to know for sure which pump you should pull up to and/or what extra stuff you add to the tank.

There's plenty of info on the web regarding leaded and unleaded fuel. I've looked through a lot of it and don't remember seeing anything about unleaded burning faster than leaded. With hardened valve seats, there will not be a problem running no-lead.

Hi
Same with me, never heard about this burning temp difference.
Lots of posts about leaded or unleaded fuel and if you have to use the lead additives on older heads.
Apparently, the US army made a survey on using unleaded gas on unhardened seats and if I remember right, they couldn't find any negative effect.
Some guys say that on normal street driven cars, you will not destroy the head seat, possibly only in race applications.
Regardless to this, I either use lead additived fuel, still avail in Luxembourg on some stations, or I add the lead substitude liquid.
Better be safe than sorry.
Gunther