[ChiefRider]

HEI is what GM called their first breakerless electronic ignition- "High Energy Ignition." Probably a homemade antitheft device.

 

[ChiefRider]

Had one similar to that in the glove box of my '69 Chevelle to disable power to the updated HEI distributor.

I had a Mallory dual point in my '64 Chevelle. That was before the HEI came out!