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69ratfed
08-06-2007, 07:26 AM
I have a 30 over 10-1 454 with Dart Pro heads, Victor Jr intake w/850 Holley and a 614 lift Comp cam. 355 rear and a TCI 400 and a TCI 3800 stall. I foul 1-2 plugs every once in a while. They are not always the same plugs. When I purchased car it had a 5-speed in it and had Autolites 3923 plugs. After we changed trans we ran the same plugs. Should I put a hotter set in or try a different plug like NGK?

Yelcamino
09-11-2007, 01:57 AM
If I remember correctly, the Autolite 3923 is a racing plug and tends to foul during street driving. I've been running Denso IK20 plugs in my AFR headed 454. They seem to run pretty clean compared to other plugs I've tried.

Go to: http://www.sparkplugs.com/

They have a nice spark plug conversion engine so you can compare brands and heat ranges... and they can pretty much get any plug your heart desires!

My427stang
10-06-2007, 06:37 AM
In my 489 Ford, I started with 3924, common one for the street for us, I found it was too cool and wouldn't foul, but never cleaned up

So I went 3926 and closed the gaps to .032 (I am not running an MSD) and it was dramatic, with no downside

So long story short, I think the 3923 would be far too cold for street driving, I would try a 3925, standard Cheapo autolight

This does assume they are getting wet with fuel and not oil fouled

MonzaRacer
10-20-2007, 05:22 PM
Well you can take every Autolite and throw them in the river or nearest recycling bin.
If everyone thinks Autolites are so good then why are none used by OEMs?
If I ha my druthers I would use AC Delco Rapidfires, besides ACs give a bettertell under boost conditions over Autolites or Champions.
A friend has started several engines and then has me come over and help dial them in. Everytime he sends his wife out and she will come back with what everthe parts guy gives her.
My buddy bought an older diagnostic machine ,an Allen Smart Scope.
Very large diagnostic tool and I learned how to use it in Tech school.
Well when I sit there and watch the firing lines dance all over because of the plugs and I can attribute the patterns to the way the engine runs, Switch in ACs or Motorcrafts (they act identical in an engine and read nearly the same) and the firing lines settle down and the idle smooths out better.
Too bad everybody gets the bums rush about how good they are then when they have tuning issues no one thinks about the plugs.