What gap do you guys like for compression ranges in the 11.6 and higher range. I know Chevy made a change in 04 from the platinums at .060 to irridiums at .039 thou. I ususally run TR6's but open the gap to .045 but this time I'm thinking i'll just throw them in at the set .040? What about heat range-I've had good luck with the TR6's-some guys prefer the TR5's or 55's? Your thoughts?

 

When I called NGK they said TR55 for the stock HP ranges, when you get about 100hp above or are running 100shot you should run the TR6s. We didn't discuss gap though.

 

I run mine at .035 for 11:1 and 150 shot.
.040/.042 is good NA

 

I'm running TR55s with .055 gap right now.

The car is running great. But, should I change them?

I'm at about 11.3 to 1 compression with my new heads/cam and .040 cometic gasket.

No problem with KR right now, running about 25 degrees of timing at WOT. 93 octane.