Dual Ignition Boxes

So I’ve gone through 3 ignition boxes in the past year. I had originally planned to try MSD, but I’ve found that MSD has even worse failure rates than Crane boxes do. I also realized, that no matter what, none of them are truly reliable. Case in point, NASCAR Cup teams have found them to be so un-reliable, they run three systems, just in case two of them die inside of a 3 hour period. Anyways, I’m not a fan of being left stranded, and the ignition box has done this to me twice now (that’s 2 times more than any of my other cars have left me stranded). Given the modifications and performance required, going to a stock setup wasn’t really an option. So I decided to take a hint, and run two boxes. I’ve wired them up so that I can switch between them without turning the key off. The switch on the left controls the switch power, and tach signal line (I had some back feeding issues so I ran then to the switch). The switch on the right switches the coil between the two units.