Went through this myself a few months ago. Driving along the highway from Lubbock to San Angelo, and truck died.
In my case, it was the coil, but it could also be the ignition module. I now carry a spare coil and module in my tool bag! Neither are hard to replace, but if ignition module, will probably need to pull the distributor.
Here's a recent thread that may be of help:
http://67-72chevytrucks.com/vboard/s....php?p=6795237
When mine went, there was a backfire out of the carb. Once I got the truck home (good samaritan towed me 115 miles or so), I replaced the coil and it started right up. Took longer to drive to the parts store and pick up the new coil than it did putting it in.
Then I discovered the effect of the backfire that happened as it died. The intake manifold seal on the rear of the motor blew out. Be sure to check for oil leaks once you replace the module or coil!