[rags429]

I had similar problem, small block 5.0--- I discovered my coil was cracked! it would run for a mile or so and then the coil would get hot -opening the crack in the side just enough to ground it out, I was in the shade with the engine running, looking at the coil when I saw a blue spark run down the side of the coil, of course it died, cooled down in a minute and started just like new---2more minutes it was warmed up and same story- crack opened and it died!! new coil fixed the problem!!