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Discussion Starter #1
I am needing to change the spark plugs in my edelbrock heads 60259. Right now I have champion and looking to go with something else. The plugs crosses over to autolites AR3924 the racing version. I was wondering if anyone runs them or just uses the standard 3924.
Also with a MSD system what are you guys gapping them? Just want to make sure I have then set correct.
Or is there a better choice for plugs this is a 100% strip only turning 6000 rpm max N/A.

thanks
 

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depends on compression and power.... and i think its a ar3934 if memory serves, just incase they(at the parts store) don't know what you're talking about... naturally aspirated, lower compression...11:1ish you will probably be alright with the non ar plug... bottled or boosted.. i go with the ar..
 

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I use standard autolite plugs 3923 on blowers and Nitrous with a .035" gap
I also build a 351 carbed with the same heads you have and put 3924 with .040" gap
I like those plugs, to my opinion,copper plugs prevent detonation.
 

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The AR's have a "coating" and the ground strap only extends half way across the electrode giving the "spark" a cleaner path into the combustion mixture. I've been running the 3924's and I just installed a set of AR3923's to see if I can gain anything from it. You want to run as "cold" a plug as you can get away with without cold fouling. My 3924's didn't look bad but had a slight brown glazed look on the tip of the porcelain, so I dropped one heat range. Colder plugs reduce the chance of detonation as well. Check out the autolite website, they have good info and pictures.

Champion plugs are NOT the brand to use in your ford. Some may say it doesn't matter, but it sure did in the 69 351W 12.5:1 motor I had in my 91 notch last year. I had been running motorcraft plugs in it, and when I went to get a new set, the parts store had stopped carrying them. They cross referenced to a champion plug, so I ignorantly bought the champions. Went to the track, and the car had slowed down significantly. At first I thought it was the heat/humidity, or my carb tuning, but before I jumped into adjusting anything I mentioned I had just changed the plugs to champions. An "oldtimer" "ford to the core" buddy of mine perked up and said their's your problem! I had the old set of motorcraft plugs I had taken out, checked the gap, reinstalled them, next pass (and the rest to follow) the car picked up over 2 tenths. Same heat range.
 

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Discussion Starter #6
Well I didnt get the plugs put in it was to hot lo. Did pull one and double checked them running a little rich but rather do that then lean. But now dont know if I want to change anything. Ran sat made 4 passes between 8.101-8.106 and 1.68 short times so was happy with that.
I dont have to worry about the part store guy looking at me funny because I work at the part store :) Gotta love that discount.
but plan on working on it thursday and putting them in and finishing up my ram air system then I will finally be done with all my mods for the year. Yippi now just got to take care of the bills :evilgrin:
 
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