Just a little fyi I thought I would pass along. My 79 F100 302 with Duraspark ignition suddenly died on the way home the other day. I took the air cleaner lid off to determine if it was air/fuel or ignition related. Since the air cleaner was off and not an issue and I could see a shot of fuel enter the carb when I worked the linkage by hand, I knew it was a "no spark" situation.
I tried cranking it again and noticed it would try to fire as I released the ignition switch. (I remembered these same symptoms about two years ago when I had to replace the pick up coil in the distributor.) It finally started then died again. I did manage to get it started and drive it home but it died two more times before I got it there.
I pulled off the distributor cap and sure enough as I suspected the wire was broke off inside the distributor right as it enters the pickup coil. The exact same thing happened two years ago and had to get it towed home. The wire was just hanging on by a thread and would intermittenly make contact.
The funny thing about this is, when I rebuilt the engine back in 1998, I replaced the original pickup coil with a new one just because it was old and had 174000 miles on it. The wire broke off the replacement 102000 miles later and this one broke off after 28000 miles.
Just a little tip for ya to keep in the back of your mind if you encounter similar situation.