GM ignition module conversion

If you want the best [ most spark energy, 0.060" plug gaps ] from the HEI module, use a 0.4 - 0.6 ohm E core coil, such as MSD #8207 or similar. Just because you are using the GM module with a canister coil does NOT mean the bal res can be omitted. Most canister coils that are used with inductive ign [ HEI, Chrys ECU etc ] are designed to be used with a bal res. This is because the coils are designed to work on 7-8 volts, NOT the full 12v like an E core coil. The coil can overheat & fail if used without a bal res. The bal res also reduces the spark energy.
So check to see if the coil requires a bal res.