76' Ford F250 {390} dying help!

Well hello guys/gals! this is my first thread and i need help. I bought a ford f250 {1976} about 5 months ago, and have put about 700 into it. It runs, and rides great. But!! I have this problem, when I am driving it, it has just died on me like I turned off the key. This has only happened 3 times, and it always starts up right away, but this can be quite dangerous in the wrong situation. Any Idea's why this is happening, what would cause this to happen? Note: evert time it has happened my foot wasn't in to the throttle. I was coasting, using very little gas, etc. Any ideas, thoughts, or advise would be greatly appreciated . . .

I have to add it's not like I turned off the key, that was a bad analagy, but that's what it seems like. Help me plz . . .

sounds to me like your electronic spark box in going bad. It is under the hood on the inner fender well. You can get them at any parts store. Look at yours and see what color it is where the wires come out of it. You will need to know this to make sure you get the right one.

check your carb linkage and fuel pressure i.e your fuel pump

I had a simmilar problem with my '78 w/460, but it didn't start again. The electric control module on your fender is a likely culprit. One definate way to tell is if you remove it from the fender and turn it over you will notice a black hard plastic. If it is cracked arround the edges then moisture can get in there and short it out. Most parts stores have them but you will need to know the color of the insert where your wires come it to it.

if it has a old point distribitor it could be the condenser