TR55 Heat Range ?
i get a little nervous with 36 degrees of timing at 6200rpm so i threw in the tr6's.
Car runs fine, no detonation.
I have read if one has a larger CI motor than the 350 and higher compression than stock, one heat range colder than stock is recommended
I was just concerned, based on the color of the plug ground strap, that going to a 6 would be to cold of a plug
On a side note I was curious if running a cooler plug could drop HC level or have any affect on it.








