[40cpe]

Less cylinders have more dwell time, increasing heat, and need more resistance. Pertronix tech told me that increasing resistance might decrease performance of the unit in higher RPMs which isn't a problem in most of our flatheads. He said the blue coil is OK with the Pertronix 1 ignitor. To me, it makes sense to run a little more resistance and take some heat off the coil and the ignitor.