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Discussion Starter · #1 ·
Is it true you can run middle grade gas in a 1970 302 and valve seats will be fine or do i need to run something else. thanks for the help
 

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depends on if the work was already done by a previous owner. you can go to your local hardware store and get lead additive, or substitute to dump in the tank if you're not sure...
 

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ok me bad did quick research i was wrong ... please forgive me ... you could buy it at the pump till 1995 ... never knew, so in other words you have to know your exhaust valve seats
 

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Discussion Starter · #7 ·
thanks for the info guys still has original kind of seats i believe, but fixen to have some work done on them so ill put hard seats in.
 

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it was either 72- or 74 when ford did it. 74 it was mandatory for all
 

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Is it true you can run middle grade gas in a 1970 302 and valve seats will be fine or do i need to run something else. thanks for the help
I have been told you can run regular unleaded for a long amount of time before the seats will wear. Changing the seats now will require major engine tear down, and changing the seats when they wear later on down the road will as well.
 

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got a question how do u know when your valve seats are going?? sorry new to working on cars so sorry for dumb questions lol
 

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got a question how do u know when your valve seats are going?? sorry new to working on cars so sorry for dumb questions lol
Eventually the valves will not seal and the engine misfire on cylinders or quit running altogether.
 

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aparently the motor had been rebuilt 25k miles ago. does that mean they changed those? motor is original its a 70...
 

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aparently the motor had been rebuilt 25k miles ago. does that mean they changed those? motor is original its a 70...
I believe so, but you will have to check with the machine shop that did the work. 25k says yes.
 

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Different parts of the country had it longer
some states still have it, its renamed avgas. you cant put it in a modern car, but i use it in my 63 galaxie with the 427 8v. The engine was rebuilt 30 years ago and hardened seats installed. But todays octane rating doesnt work with this motor. I dont use it necessarily for the lead but for the 109 octane.
 

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I believe so, but you will have to check with the machine shop that did the work. 25k says yes.

im gonna say yes then, cause it was in the last 3 years when he did it. so i think its safe to asume it has been done. thanks for the info. good thread too!:thumbsup:
 

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Or you could always run a little Sunoco Purple 100. It's leaded. I always mixed it with 93 octane in my street bikes. Smells good too. :thumbsup::D
 

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yes you can but...

Or you could always run a little Sunoco Purple 100. It's leaded. I always mixed it with 93 octane in my street bikes. Smells good too. :thumbsup::D
in my area, the only place you can get purple is at the track which is at least fifty miles away. I can get avgas down the street. plus avgas is $4.50/gallon. no mixing necessary
 

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As discussed your valve seats should be fine so what grade will depend on what your compression ratio is. If it pings and you think your overall advance is right, go with the higher octane.
 
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