Plug questions

[LS What]

I would like to try denso irirdium plugs in my 92 coupe, 308 TFS Novi 2000. I don't know what part number to use though. Presenty using NGK v power R5671a-7 stock no. 4091. Can anyone help or have suggestions. Thanks

[david powell]

those ngk 7's are way too high of a heat range for what you are running ,you need to be running 9's

[LS What]

Those are the plugs my friend Bob(renegade king) told me to run so thats what I bought. The car runs good and hasn't broke anything besides two t-5's.