Hei /6 won't shut off?

Excellent work. Kit is one of the electronics experts here, so good he chimed in. I agree that you should run a dedicated ground wire to a mounting screw on the HEI module, and also that an e-core coil would be better. Skip White sells a pretty one for ~$20 on ebay, but giving overseas shipping, you might use a factory one. If they have 90's Dodge trucks or Jeep Grand Cherokees w/ 5.2/5.9L engines there, might use a coil for it. 90's GM or Ford are similar.

I also mounted an HEI module on an old PC heat sink (w/ thermal compound). But, I used the later 8-pin GM HEI module since better sealed connectors, and simple to use the GM coil since easy plug n' play. TrailBeast sells a kit of new parts if junkyard doesn't work for you (85-95 GM V-8 trucks, cars to 93).