what is the plug do you run best with,i find out that 400 will always run with a 8 plug,
hotter pipe make most power,i'm wondering why HPD suggest a 9 plug,i've tried a br9es and i can't
reach the exhaust temp anymore than 1050-1100 degrees max at wot even with a 168-170 main,fully race ported,15.5
heads.i'll go back to br8ES today.
there is a mojor differences on this motor from a br8es to a br9es plug,watch out your plug color and digatron.