Noisey Fuel Injectors

I have a ticking/tapping sound that I have determined to be coming from the fuel injectors (30lbers). I put a two foot wooden dowel up to my ear and touched each fuel injector. Some are louder than others. Is this normal? If not, what causes it and will it cause any serious problems if I don't address it right away? The car is running fine and has full power, just this annoying tick. I'm going to be taking my car to Belmar, NJ this weekend and I just want to make sure everything is ok.

Thanks guys.
 
Some injector pulse noise is normal, but should be hard to hear, especially on our motors. Its more noticeable on quieter engines like the 4.6. Do a cylinder balance test, and see if any show up, and if they match the ones that sound louder.