I have a 1978 F250 Club Cab, 351ci. The engine has just started turning itself off after running for a short time. All the wiring appears intact and corrosion free. I recently installed (500 miles ago) an alternator and voltage regulator. the engine starts back up immediately and runs fine for a few minutes and then it shuts itself off again. Any ideas?

 

Often times, if the motor cuts out like you shut it off with the key, it's a sign that the ignition module (mounted on the driver side inner fender) or pickup module (inside the distributor) are failing. You can test the pickup module with a multimeter; unforunately about the only end-user way to check the pickup module is to put it on a machine at a parts store, but the tests are often inconclusive.

 

you can test all your ignition parts at home.
you need both a DVOM and an analogue one to do all the tests
I dont have an analogue but it wasnt too hard to rule everything else out when the pickup in the dizzy died on mine.
autozone website has a great duraspark troubleshooting guide that I used to find my issue

 

I have been running dents for the better part of 20 years and I always carry a spare ignition module behind the seat, because this has happened way too frequently to my dents. In my off road truck I actually put two of them on a aluminum plate side by side so I could just unplug one and plug in the other. One of the joys of the duraspark, but they are really cheap now they used to be over$100 now the they are around $20. good luckTom

 

Yes yes got to love the duraspark.... i have went through 3 boxes in like 2? weeks or so.. Been thinking of goin over to an HEI setup. One of my buddies got a built 460 down in his 86 4x4, well he went to that setup and told me that was one of his best purchases!!

 

That's a lot of boxes...I'd be more concerned you have an overcharging issue that's frying boxes.