Putting that HEI module inside a steel box is roughly equivalent to baking it in an oven- - - - -it will eventually cook itself due to lack of ventilation. I like to use a finned aluminum heat sink to mount solid state switching devices, and hide them under the dash or somewhere else out of sight, with good airflow around them. For instance:

www.ebay.com/itm/256798573129?

A more commonly available and less expensive trigger device than the MOPAR pickup coil would be the 6 cylinder HEI pickup, with a simple triangular piece of steel mounted to the distributor shaft to generate the sine wave to turn the module on and off. There are lots of them available on Ebay, and their signal is exactly what the HEI module is designed to function with.

www.ebay.com/itm/156768449356?

Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!