Not to bash on MP electronic ignition because the OEM boxes are great, but this is why I switched to HEI. I got sick of my aftermarket boxes failing. Had a couple of ballast resistors fail too.
OEM boxes are too hard to find so I gave up and went HEI.
Best to steer clear of FBO for anything other than their limiter plates. See this thread:
FBO Systems
It seems that their boxes are nothing more than HEI modules with a rev limiter built in. Greatly overpriced.