Changing out even low-end conventional oil every 3,000 miles should be enough to prevent any of the problems you mentioned. Even a buck-a-quart Havoline, Shell, or Citgo will not be stressed or depleted over a 3K non-Severe Service interval. There's exceptions to all such beliefs of course, but they're far from the norm. Amkeer's recommendation of 7K changes with syn might be reasonable as well if you want both syn and peace of mind -- personally I'd go 7,500K in your shoes since I assume that's the Dodge spec..?
Depending on where your oil filler cap is located, you may be able to survey the valvetrain with a flashlight and keep tabs on sludge/varnish build-up, if any. If you don't see any gunk goin' on, I wouldn't worry about your oil change intervals, and move on to other matters, such as contemplating when Britney Spears will finally pose for Playboy.
[ May 05, 2004, 04:50 PM: Message edited by: TC ]