360 Spark Plugs

Sterling

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I am working on my buddies 71 Demon, I built a 72 360 engine for it. I had it out 2 weeks ago, and it fouled all the Autolite spark plugs he had in it. It hafd a carburetor problem, so I put a known good carb on it, and a used set of NGK spark plugs that were one heat range colder. It is running fine now, but trying to source the correct NGK spark plugs has been a problem. All I can get are resistor plugs, and that is not what I prefer. It is a factory electronic distributor, old chrome box and old Mallory coil. Anyone use resistor plugs in place of non resistor ? Took me a week to get 8 spark plugs from my NAPA.
 

jazak5

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E3 .46 and wont go back !!!! no fouling/better idle/cleaned up the throttle response on the same engine with no other changes !!!!!!
factory spec 340
pertronix distributer conversion with correct coil and taylor wires
 

stroked340

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Autolite 3924's run them in both my 360 and 416 stroker..
 

GTX JOHN

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I have never noticed any problems with using resistor plugs
even on the race cars when that is all I can find.
 

Sterling

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Thank you for the replies. I just got a set of Champion N12YC, and a set of NGK BPCR5ES plugs to try.
 

toolmanmike

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I am working on my buddies 71 Demon, I built a 72 360 engine for it. I had it out 2 weeks ago, and it fouled all the Autolite spark plugs he had in it. It hafd a carburetor problem, so I put a known good carb on it, and a used set of NGK spark plugs that were one heat range colder. It is running fine now, but trying to source the correct NGK spark plugs has been a problem. All I can get are resistor plugs, and that is not what I prefer. It is a factory electronic distributor, old chrome box and old Mallory coil. Anyone use resistor plugs in place of non resistor ? Took me a week to get 8 spark plugs from my NAPA.
You didn't mention what Autolites were in the engine.
 

toolmanmike

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I have ran Champions in both my old Mopar's with no issues. I have owned Mopar's since 1970 and have always ran Champions with no issues. I have had fouling/heat range issues with Autolites twice. Run what ever you want. If you have troubles switch to something else. IMO NGK is probably the highest quality/ best built plug out there. Plugs are like what oil or filter brand is best. Whatever works best for you.
 

toolmanmike

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They were Autolite 55
They should be 66's according to the chart I saw. 55's are probably way too cold and no wonder why they fouled. I tried Autolites in my 273 once. They were too cold and the engine ran like crap. No misfire but a rich running I couldn't tune out.
 

Sterling

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I thought that the 65 was a resistor plug and the 55 was the non resistor, but that was a long time ago. I have a couple options now
 

toolmanmike

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I thought that the 65 was a resistor plug and the 55 was the non resistor, but that was a long time ago. I have a couple options now
Could be. I didn't see 55's listed.
 

Bewy

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Choosing spark plug brands is like picking which issue of Playboy magazine was the best....

Tests I have read & heard about show res plugs do NOT loose any HP to non-res plugs.
 

memike

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I have ran Champions in both my old Mopar's with no issues. I have owned Mopar's since 1970 and have always ran Champions with no issues. I have had fouling/heat range issues with Autolites twice. Run what ever you want. If you have troubles switch to something else. IMO NGK is probably the highest quality/ best built plug out there. Plugs are like what oil or filter brand is best. Whatever works best for you.
Spot on, well said and could not have said it better. NGK plugs are number one in my book, and I ran Champions when NGK plugs was not on the shelf at our local auto parts , and ran them threw the year or two in my 318 drivers.
 
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