3 ohm vs 1.5 ohm ignition coil
Any ign system that uses a coil with a 3 ohm primary resistance is going to have low-ered spark energy. The GM HEI system replaced a points & bal res system in GM cars that had very similar characteristics to the Mopar points system. The HEI with it's 0.6 ohm coil produces 85% more spark energy than the points it replaced.
So I would look for a better ign system &.............Pertronix would NOT be high on my list...