<VV> Autolite plugs

[Smitty]

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.
Somebody asked how old I am.  Several years ago when I was 69 I lost four 
friends at the age of 74.  I determined that wasn't going to happen to me so 
I quit having birthdays.  I tell people I was 69 on my last birthday.  Go 
ahead and scoff.  It's working.