Timing chain guides?

The factory installed timing chain tensioners on the 3.9l V6s, and with the "silent chain"- I've never seen one factory installed on a Magnum V8, although people regularly use them. You'll get recommendations from both sides of the fence on this one, don't use them/use them. A good quality timing chain with no slack shouldn't need one; but if you've had any line boring/honing done, you may. Your choice, but I will say this: if you do use one, get a good one; the quality of the plastic used for the rubbing blocks can vary.