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Discussion Starter · #1 ·
Hi all
This question may be so basic that it doesnt' even belong here, but indulge me please. I acquired a "built" chevy 350 bored .60 over torque plate. The engine has a comp 12-250-3 cam and an Edelbrock 750 cfm performer carb, Weiand intake manifold, older style HEI ignition, and Sanderson headers. That's about all I know. So, does it make a big difference which spark plugs I use. I want to change them, simply because I don't know how old they are, and they seem a little bit fouled. What do I need to use, or what must I avoid. Is there any risk with the plug being too long? Any help is appreciated. John
 

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Do you know the compression ratio? The only reason i ask is sometimes domed pistons sometimes cause a problem.

Do you know what the heads came off?

if they are standard wedge heads i would just go with spark plugs for something like a '79 Camaro with a 350. The reason being that car should have an HEi unit and the plugs should be the correct heat range and gap.
 

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I would remove a plug and get the brand and number off of it. You didn't say if it was the peanut plug or the big old style. The big old plugs could be Champion RJ-12 Y or colder heat range RJ-10 Y. I don't know the numbers of the peanut plugs.
Dave
 

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Discussion Starter · #4 ·
I don't know the compression ratio. I can easily remove, and then replace the existing plugs, with the same type. One of my thoughts was if I could upgrade to something better, but I don't know if there really is a "better" spark plug. I was looking at the splitfire plug, but really don't know if it's any better. Is the cumulative opinion to simply pull a plug, and replace it with the same thing? I agree with the comment about the '79 camaro engine. I'll bet that that's close to where my engine came from. I also know that I have a 10 bolt posi rear end, that I was told came from a Camaro, so it's quite possible the engine came from the same car. I'm pretty sure the heads are cast iron, nothing special. They may be camel hump heads, there is a grooved carving in the heads that looks like two humps. I also notice that on the passenger side, there is only a single threaded hole drilled into the head. The hole is on the upper end, toward the outside of the engine. I don't know if that helps. John
 

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San Carlos, eh? I grew up in Belmont. My old stomping grounds so to speak.

I went to the ACDelco site and they gave R45S for my 350HP 327.
 

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Santa Clara. We have lived here for 25 years now.
The only way to tell exactly what heads you have is to pull the valve cover, there is a cast in number right about in the middle.
I think the double humps were on a few different versions. Look at this web site....
This site has head numbers.
 

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Discussion Starter · #8 ·
Vaughn, That is a great site for future reference. I do need to figure out what block and heads I have, since it will make things much easier in the future. That, and I've been cruious to know exactly which engine I have. Santa Clara...my old stomping grounds. I went to Santa Clara Univ, 84-88.
John
 

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warpwr said:
San Carlos, eh? I grew up in Belmont. My old stomping grounds so to speak.


Hey Bella I work in Redwood, just yell if you ever need any help or just want to show off the car.:D

Randy
 

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Discussion Starter · #12 ·
Randy

I also work in RWC, and I drive my car to work about once a week in the dry months. If you ever see a pink "hot rod" style Bel Air racing up and down Veterans Ave on my way to Kohlweis Auto Parts, that's me.
John
 

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BELLA57 said:
Randy

I also work in RWC, and I drive my car to work about once a week in the dry months. If you ever see a pink "hot rod" style Bel Air racing up and down Veterans Ave on my way to Kohlweis Auto Parts, that's me.
John
I'll look for you, I use Maple and Veterans getting over to 300 Bradford each day.:cool:
 
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