I recently have been having this problem where my truck will drive for a while and die at the worst time like an intersection or miles from anyone. I thought it was the power cables hooked to the battery for the MSD ignition when this first started happening I replaced the connections and it didn't happen for a while. Then I was driving along and at a intersection the truck died and I tried to start it, it would just turn over until the battery was dead. I checked the spark plug wire for a spark and there was nothing. I got it to start again after a while and then it just stalled out once again this time I was still in the parking lot of a store so that was good. I removed the after market ignition stuff and plugged the old HEI stuff into the distributor and it still didn't have a spark so since its been a while since tuned it up I did a full tune up that included; spark plugs, cap, rotor, wires, coil, oil, oil filter and air filter. After I did all this I tried to take it out for a test drive and it only ran for about ten minutes in the yard before I took it out. It got across the street before it died out again with no spark. I thought it might be a the HEI ignition module so I took that off and went to auto zone and they tested it. There was a row of red lights on the top that went to green as it was tested. When since my truck wasn't doing the stalling out thing right then I ask them to test it a couple of time until it got warm. It kept working after ten try's like it should and then one light (the dwell light) stayed red. Then he tested it a couple more times and it worked again like it was meant to. I decided to change that as well just to be sure. I thought that after all this I would have it working properly again so I took it out and it stalled just like its been doing. There is no spark going to the spark plugs. There is gas and it does turn over. I am out of ideas though. I need alittle help to track this problem down. And some diagnosing help also.
Thanks in advance, D.L. Man
P.S. Sorry for talking you ear off.