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  • 1965 - 1973 Classic Mustangs -General/Talk-
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SPARK PLUGS?..

  • Thread starter Thread starter 6FIVE_STANG
  • Start date Start date Jan 4, 2007

6FIVE_STANG

New Member
Jul 2, 2006
142
0
0
San Jose, CA
Jan 4, 2007
#1
  • Jan 4, 2007
  • #1
I have a 289 and i just installed a MSD setup a few days ago, I need new spark plugs but i dont know what to get! (size, tip material, heat range??...)
what should i get?
 

fasttback

New Member
Apr 16, 2005
471
0
0
Northern CA
Jan 4, 2007
#2
  • Jan 4, 2007
  • #2
First we need to know what heads you are running? Also knowing your compression ratio may help you choose a plug temp to start?

There are numerous sites that have some useful info (here are a couple):

http://www.centuryperformance.com/spark.asp

http://www.dragstuff.com/techarticles/how-to-read-plugs.html
 

6FIVE_STANG

New Member
Jul 2, 2006
142
0
0
San Jose, CA
Jan 4, 2007
#3
  • Jan 4, 2007
  • #3
STOCK 289 HEADS.
 

fasttback

New Member
Apr 16, 2005
471
0
0
Northern CA
Jan 4, 2007
#4
  • Jan 4, 2007
  • #4
18mm thread. My last set I used Autolite 45 (heat range 5) on an Mallory ignition. Compression was 9.5 to 1. It's best to read your spark plug after running it.
 
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