I have a 2004 Silverado with the 4.8 in it, I dropped it off at the body shop for some collision repair and when I picked it back up it kept dying. In a 5 mile trip it cut out 10 times. I could put it in neutral and it would fire right back up with no problem. It never stuttered or acted like it stalled, it would just turn off. Any idea what I'm looking for here?

 

I'd check you main grounds.

Really hard to say without knowing what work was done at the body shop, grounds are the only thing I can think of that they might have to mess with.