Iron,
An E core coil usually runs without a bal res & draws too much current to be used with either points or the Ch ECU. If you can find an E core that uses a bal res, then it would be ok to use. And it would be worth it because the E core design delivers more spark energy, all else being equal. The Crane PS91 E core coil can be used with a 1.2-1.9 ohm bal res [ Echlin ICR23 or Wells CR107 ]. Not sure if Crane coils are still available.
The MSD 8207, Summit 850500 & 850615 are all good E core coils but not sure if they will work with bal res. You would have to check.
