5.9 mag in a 65 coronet, using stock efi injectors and TB, with MS2 running it.

Not everytime, but more often than not, the engine will shudder or skip.
if I am driving, I can hear it catch and feel the loss of power, and sometimes when I am stopped at a light, it will kill the motor. Like I turned it off.
It restarts instantly, or if I am driving, it just skips a beat and keeps going.

There isn't any diesling or chugging when it quits at a light.

I can't recreate it consistently either.

A couple of years back I did have to replace the coil. Stock coil driven by the ms2.

It idles fine when it isn't happening.

Anything obvious I should check for?
Having a hard time wrapping my head around what might cause an intermittent miss like that.