Not to question your diagnosis, but are you sure it's a miss? Meaning are you sure it's an ignition issue? Have you pulled the plug wires one at a time to see if it is one particular cylinder?
It sounds to me like a vacuum line problem. Those little bastards can cause stuff like that and are easy to miss.
Spark plug gap is .028", but honestly, I changed the plugs when I bought mine and they were .040
and it still ran/idled smoothly (runs better now,though!)