What could cause cylinder to have barely a spark?

What could cause every other cylinder to have barely a spark. The other cylinders have a good crisp spark? It has an FireBall electric ignition.

I looked online for the firing order and was able to get it running but it runs rough, not sure where to go with this. The Fireball electronic ignition some how went bad, so I was told to replace it. It has spark but only every other cylinder has a good crisp spark. Every other cylinder has a very weak spark.

Its a little over my head ill admit. Cylinders 1, 7, 4, &6 are the weak spark. My Boss can't help me and he has 40 yrs in the automotive field. I'm trying to help a fiend and I'm stuck. It has had a lot of different hands on it that shouldn't of had. Nightmare