My truck kept cutting out and wouldn't start after a nice long drive in the rain to class. Turned out to just be water in the distributor like I had expected. A new rotor ($13) and cap ($40) replaced the corroded ones. It restored a little lost high end power (nothing on the low end though). Also helped out with the frequent downshifting into 2nd while traveling West Texas hill country. JFYI

I got two Silverado's 2003 and so far we have had 9 rotor caps replaced.

Not cool.