Which Plug?

[SBeeMan]

I've got a 340,.30 over,12.5:1 compression,Eddy heads ported,259in 274 ex .600 lift roller. Gonna bracket race the car only. What spark plug you guys running with this sort of combo. I've only run big blocks in the past. Thanks

 

[70aarcuda]

NGK Spark Plugs R5672A-8

 

[SBeeMan]

Thanks Cuda