HEI in Mopar ECU casing

HEI module mounting holes have a metal insert in them, those inserts are the ground point for the module. You will need to solidly mount the module to the mopar brain box to ground it, then ground the box to the inner fender.

Yep you can make the ballast into a jumper, but i would dig out all the potting compound, and remove the old resistor wire completely leaving just the 2 brass terminals on either end then solder in a jumper wire. Thats how i did my ballast resistor, then i filled it back up with 5 minute epoxy.