I have a 96 Sierra with about 190,000 miles. In the past three and a half years I have put 3 cap and rotor sets in it. I get about a weeks notice where it will take just a bit longer to start in the morning..then one day...it just won't fire. I replace the cap and rotor (both are heavily charred) and then in 12-14 months it does it again. I know that they changed the cap style in 96 from the 95 and earlier and that the new style cap only has two screws holding it down and it is much shallower. Could I be getting moisture in there? That's the only thing I can think of unless it's unique to my truck.
