Autolite double platinum plugs? Also indexing?

[SSDiv6]

Originally Posted by art leong

Are they good for a racing application? Naturally aspirated. 13.5 to compression.
I've never used them, but they are a semi retracted tip (half way between the plugs I am currently using and the stock champion plugs) plug with a fine electrode.
They will fit without worrying about the pistons colliding with them.
Also how should the plug face. If I use the indexing washers?

Art,
Double Platinum plugs were not designed for a high compression racing engine; the Platinum coating is just for protecting the electrode from wear and corrosion; designed for daily use and a longevity and not performance.
Find a real racing plug that has a colder range than the current OEM plugs and see how a bare or Copper, non-resistance electrode plug works for you.

Also, my preference have always been the racing plug offerings from NGK or Autolite.

http://www.ngksparkplugs.com/docs/RacingSpecs2010.pdf