Curious what heat range you all are liking on N/A BBC? I have 735HP 572's with Edelbrock 355CNC heads....NGK? Champ? Others?? Thanks, Tim

Have had excellent luck with ngk v power over the last 20 years 11-1,10.5-1 and 9.5-1 compression BBC's, also run them in my supercharged seadoos and canam atv's

i run 7's mostly unless the plug reads hot or fouls

We ran NGK - 11 in my Blown Alky motors (very cold) so 7 must be "hot"??

An NGK 6 is equivalent to and AC 43 which is stock for Merc NA engines.
An NGK 8 is equivalent to an AC 41 which is stock on older Merc SC'd engines.