Duane,
If you have stock spare tire carrier, check for rattles in this first. That's usually the worst back there. You can sometime quiet your stock supports if they are missing the rubber insulators that are missing on the tailposts. There are also tiny push-in bumpers at the top of the tailpost (insulate tailgate to tailposts) that a lot people miss (especially after paint). They go in a little 1/4" hole or so. These cheap little babies make a big difference.
The poly hinges fit good, but unless your tailgate is totally loose back there and your suspension is rock hard, the factory ones should be causing a ton of noise. Not trying to not sell you on them. I've used BCs cables and the poly bushings and liked both, but just saying make sure you fixing what needs fixing.