Spark plugs
 

I gotta change my plugs in my Hemi and was just wondering what would be the best plug for a street/strip motor. I have autolites in it now. Thanks

Re: Spark plugs
 

I really like NGK's street/race plugs. I have them in my race car and my street/strip car. I used to run autolights in both.

Re: Spark plugs
 

Champion 300 ..... old # N9Y for 426 Style Engine if Comp. is not over 11.5.
Don't know if you were taking about this gen of engine from post.

Re: Spark plugs
 

Ya it's the old style 426 Hemi but a Mopar crate one. Sorry about that. Thanks though

Re: Spark plugs
 

My street hemi (10.5:1 C.R.) likes N12Y Champions. The colder plugs foul within 3000 miles. The race hemis (11.5 or greater C.R.) work fine with N6Y Champions. I've tried NGKs. They didn't work any better or worse than the Champions. I tried Autolite's and AC. No luck with either as their heat range selection is not as good as the Champions and NGKs. In the street car I gap the plugs at .035 and the race motors are gapped at .040. The street motor has a stock dual point and stock coil. I've run a Chrysler silver box, a Chrysler gold box and a MSD-7 on the race motor. I wired them side by side. Made 3 passes, with no difference in performance.

Denny