<VV> Autolite plugs

[Bryan Blackwell]

Hi Smitty,

I found the following on the Autolite web site:

http://www.autolite.com/sites/default/a/uploads/en/auto_crossref_0311.pdf

To answer your question, the 275 = 44FFS, 425 = 44F.  They also list a couple of others that these numbers replace, so my guess is the big difference is the threading, not the heat range.

--Bryan

On Aug 13, 2010, at 11:52 AM, Smitty wrote:

> Smitty Says:  I have been using Autolite 425 plugs in my cars for years. 
> Even in Spike the Turbo because he spends 95% of his time on the street. 
> The porcelins range from almost bone white to dusty gray depending on how I 
> have been using the car.  Members have said they are happy with 275s.  That 
> sounds a long way from 425.  Does anyone on the list have information on 
> Autolite heat ranges?  I would like to try some adjustments just for the 
> track.