just a little curious, what type of power level do people start using 8 heat range plugs instead of 7's?

i know personally ive been using bkr7e's gapped to .020 all stock ignition otherwise making low 400hp range for a while

 

I ran 8's in a 8.0:1 comp turbo LS with no turbo on it for 2 years. And it was gaped down to .032 without any problems what so ever.

 

i would have recomended 8 at your level im on 9's at 422 and pump gas

 

I run 7s at 630hp for years. O ya on stock ign. gap at 20.

 

i run 8's all the time....even 9's ....as long as the setup is tuned to NOT run pig rich all the time the plugs stay clean and don't foul out.