# Unleaded Fuel Question??



## DJN (Apr 6, 2010)

Should I be running a lead additive in my 1969 GTO? Car has a 1969 -400CI motor in in but I'm not sure what valves are in it...


----------



## jetstang (Nov 5, 2008)

Yes you should. Check the head casting numbers and see if they are 69 or not. The valves don't matter, it's all about hardened valve seats. If your planning on tearing the motor down in the near future and having hardenned seats installed, I wouldn't worry about it. Or if the builder put hardenned seat in it. If the heads are 74? or later, they will already have hardenned seats.


----------



## DJN (Apr 6, 2010)

jetstang said:


> Yes you should. Check the head casting numbers and see if they are 69 or not. The valves don't matter, it's all about hardened valve seats. If your planning on tearing the motor down in the near future and having hardenned seats installed, I wouldn't worry about it. Or if the builder put hardenned seat in it. If the heads are 74? or later, they will already have hardenned seats.


Thanks, so it can't hurt to add it since i really don't know right?


----------



## jetstang (Nov 5, 2008)

It won't hurt anything to run it as you don't have a catalytic converter. It is about $10 a tank to run it, so I change over to hardened seats as quick as I can, or not worry about it and plan on a head swap. Most of these cars are limited use, couple tanks a year, so just run the additive.
What numbers are on the middle exhaust port on the engine, inch high numbers on both exhaust ports. That will tell which heads you have.


----------



## DJN (Apr 6, 2010)

jetstang said:


> It won't hurt anything to run it as you don't have a torque converter. It is about $10 a tank to run it, so I change over to hardened seats as quick as I can, or not worry about it and plan on a head swap. Most of these cars are limited use, couple tanks a year, so just run the additive.
> What numbers are on the middle exhaust port on the engine, inch high numbers on both exhaust ports. That will tell which heads you have.


I'm off to Cabo for a week but I will check it when I return and will PM you with the numbers.


----------



## 68greengoat (Sep 15, 2005)

jetstang said:


> It won't hurt anything to run it as you don't have a torque converter. It is about $10 a tank to run it, so I change over to hardened seats as quick as I can, or not worry about it and plan on a head swap. * Most of these cars are limited use, couple tanks a year*, so just run the additive.
> What numbers are on the middle exhaust port on the engine, inch high numbers on both exhaust ports. That will tell which heads you have.


Heck, I have run 3 tanks thru mine already and I live in the northwoods where spring starts late...... Drive 'em man!


----------



## jetstang (Nov 5, 2008)

68greengoat said:


> Heck, I have run 3 tanks thru mine already and I live in the northwoods where spring starts late...... Drive 'em man!


Duh, you get 2 MPG, you use a tank to do a beer run.. 
I was trying to justify adding $10 to a tank of gas for lead additive, I swapped heads because I was too cheap to buy it.. Well, I actually am not using my 389 heads because of it, or buying dished pistons and hardened seats. I have a Lemans, I drive mine, but you know GTO guys, lol.. OK, I haven't driven mine that much, too hot in FL, and havent' got the AC working yet, but this year after paint, time to cruise.


----------

