When it was cooler days , the truck would have less of the roughness and surging in the idle. This was a little worse when it started getting warmer. I have the vented distributor cap so I think inside it should be dry....
But Mom and I both noticed after changing grades, that it runs better, rain or shine. Big rainstorm while we were out this afternoon, and it ran great during this. Same as yesterday when it was dry and in the mid 90s.... The gas change has made as much difference as the tune up (cap/rotor/plugs) did. Remember, when we got this one, it had been sitting around a lot, and I had to run a couple tanks and Berrymans B12 Chemtool to get the nasty old gas through it. It's always run strong on acceleration, and quick off the line, but it's never enjoyed idling. Like it's saying, "Mom....you know I wanna get out and stretch my legs, not sit around doing nothing...."