Spark Plugs
#1
Trying to figure out what type of plug to use. I need the long reach plugs, have Dart Iron Eagle heads. 532 CI, hydraulic flat tappet cam, 1050 Dom. carbs on 2" spacers, HEI dist. Dart is recommending NGK 5155 FR-4 or NGK 7373 FR-5. Any thoughts?




