I am looking to install a new voltage regulator on a '67 GTX. When the car was running there was a small "wift" of smoke every once in a while from behind the old one mounted to the firewall. When mounting the new one, does one of the mount bolts act as a ground for it or should I mount it using the three rubber bushings that came with it? The old one was loosely attached and if it needs to be grounded, that could have been my issue. Thanks, Eric