Take the plug wire off put a plug in the wire and lay the plug on the side of the engine compartment makeing sure the head of the plug is grounded to the car then turn over the engine. Make sure you unplugged all plugs, so the car doesnt start. you will see the spark if it is there. I wouldnt think the ingniter connection is bad, I would blame the igniter they go out easily, especially since they are old as hell.

If I was you, I would convert to Direct Fire and after you converted if the problem still exist then start to worry about it again. you can use stock 2nd gen coil and igniter, then theoretically you will have an extra igniter, but I think your trailing igniter is gone. If you convert to direct fire, you run one coil per plug on your leading plugs and the plug wire goes straight from the coil to the plug, bypassing the shitty dist ! ! ! Doesnt that sound better to you?