Engine problems at 3k to 4k rpm
I have an '04 Kingpin, it was sputtering and missing at approximately this range, it turned out to be a leaking fuel injector o ring. If you have the S&S airbox, this is a lot easier to fix I am told by my dealer. Anyways, I am having the dealer put the S&S in while he fixes the o ring. You may want to check in the *** forum as well.
I live in SC, so can't help you with finding a good dealer.