HEI or Rev-N-Nator and several HEI questions

I've had several rev-n-nator boxes I've had good luck with them. One was on my Demon with a 416 stroker, it really helped with starting and high rpms. I have one on my Dart 340 roller motor with Holley fuel injection had a little issue with it picking up some interference but they helped get it resolved and hopefully it's fixed.