Well, the fact that you are getting a strong spark out of the coil means:
1. coil module is ok
2. getting a signal from the optispark to the PCM
3. you are getting a control signal to the coil module from the PCM......
So, exactly where are you checking the spark? Right out of the coil end, or out of the end of the wire that is going to the distributor?
When you changed the optispark, did you reuse the cap, or use the one that came with the new optispark? What about the rotor? Reused or new?
Are you absolutely sure it was installed correctly?
If a new cap and rotor was installed, and the distributor was installed correctly, I would be leaning towards ignition wires......
I hated Optispark.....at 100K, that was tuneup time, if it even lasted that long.....someone comes in for a tuneup with his Firebird, and you better have a pillow to throw under his head when he passes out after you tell him how much it will cost.......cap, rotor, plugs, wires, w/p, coolant, air and fuel filters, pcv(?)......then there is the labor time for those plugs.......the labor time for those wires.....we always RECOMMENDED w/p replacement if it was never replaced.....last thing you want is coolant coming out of that weep hole in the pump and taking out your Optispark.......