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Discussion Starter #1
my GTO 65 is equipped with electronic ignition; does it affect the kind of plugs?
should I keep the AC44S spark plugs or should I changed them for another model?
:frown3:
 

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My car has an HEI distributor and has ac delco r45tsx plugs and seems to run fine hope that helps. pretty sure they are gapped at .06"
 

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Discussion Starter #3
the R44S are gapped at .035";
to be honnest, my car runs fine too, but I wonder if the firing is the same quality;
 

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the R44S are gapped at .035";
to be honnest, my car runs fine too, but I wonder if the firing is the same quality;

Sometimes they do run better with a tighter gap. Factory of Pontiac is .035" for points distributors while .060" for the HEI distributors. The wider gap requires more energy to jump.

Personally, even on electronic ignitions, I like to keep mine at .040" knowing that over time, the electrode errodes and rounds off causing the gap to widen a little and will take more energy to jump the gap. But .035" if it is working for you is just fine. Keep in mind that power adders like nitrous or boost usually call for very tight gaps with some running .025" or even less because increased cylinder pressure from these power adders can makes it harder for the spark to jump the gap.


Stay away from Platinum plugs according to this article, "It is best to use a non-projected type plug. Projected plugs allow a greater portion of the electrode to be exposed to combustion gases and possibly cause pre-ignition. Also, we recommend that you do not use platinum plugs. The platinum tips can get extremely hot and will cause detonation. Plus, there is a chance the tip may break off even in mild cases of detonation and can severely damage the engine."
 

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Just thought you'd want to know that the r45tsx plugs are for later model heads, generally from the '70's. Your GTO has the correct plugs.
 
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