I was reading on NGKs website that the TR55s are for a NA motor. And the TR6s plugs are for high compression motors or N20....

I am currently running the TR6s plugs in my CAM ONLY stock H/I car. I am making 415/378 at the rear.

Now in the spring i am adding 42# injectors, 85mm Lid, 85mm Maf and an E-CutOut.

Should i be running the TR55s or TR6 plugs? What should they be gapped?

 

What kind of shape are the tr6's in when you pull them? If they are a little rich you could try the tr55 which is a hotter plug and see if they clean up some. If the tr6's are a nice gray color I would leave them alone.

 

if u are running N/A go with TR-55 , if nitrous TR-6

 

TR55s with .045 gap

 

I have not pulled any plugs. Will not see my car till tomorrow....

 

I would check them like said above and see what shape they are in. Then either go down or just keep them. I had the Tr6's in mine while I was cam only for 1 1/2 years and had no problems.

 

I am not having any problems either, was just woderign what would be the correct plug to use.

I have ran the TR6s since 2/2007. That is what my tuner recommended me to run. And i have only put on 7k miles since then

 

NGK TR55 for stock. NGK recommends you drop one heat range for every 100 hp the motor is built over stock. I would stay with the TR6's myself.

 

I would stay with the TR6's.

Bill