GM control module

What I said in post #7 was correct, & is correct in this post.
If the coil being used was designed to be used with a bal res, the bal res is STILL NEEDED when used with a GM HEI module.
People may have omitted the res, but would run the risk of overheating the coil.
The coil & res form a voltage divider network. The coil gets less than 12v because some of the voltage is dropped across the res.