Which coil?

Using a 0.6 ohm coil, with or without the bal res, will create issues. Without the bal res, it will probably take out the power trans in/on the ECU from current overload.
The ECU is designed to use a 1.5 ohm coil with a 0.5 ohm BR.

You could use the 0.6 ohm coil & improve your ign system at the same time by eliminating the ECU & bal resistors & using a GM HEI module. Simple, easy, better, pics on the net.