1995 Chevy Camaro Fairly simple ignition question.

I have a 1995 Camaro z-28 with 160k miles. The car has been very well maintained but has been having some ignition problems. The car will start fine (Sometimes) but after it runs for a while the car will stall out and die suddenly. I check for fire at the coil and found that there was none. I replaced the ignition coil and there is still no fire. I wanted to know if the optispark delivered signal to the coil. Or if the the coil sent the signal to the Optispark, and if it does, what sends signal to the coil? I have also noticed that there is a fair amount of dirt/grime/oil on the optispark, so I am currently leaning towards opti failure. I just wanted to get a second opinion before i spent $550.00 on a new MSD opti. Thank you so much for your help! I will be sure to donate if you help me out!!