After doing new valve job, intake to head matching, some head porting and carb adjustment, I am looking for the spark plug heating range.
After a 60 miles nice flush ride on mounten and back roads the outcome is:
AC Cobra 289 NAF - YouTube
Left plug is NGK BPR 6 ES (cyl. 6)
Right plug is NGK BPR 8 ES (cyl. 2)
There is nearly no exhaust soot on side pipe end.
Which plug would be better?
Rico