So are you saying this is normal? I did rotate the wheel in neutral by hand today, and did find some slop in one place that is probably causing the sound. Is this the bearings or the final drive?
Perhaps a definition of "slop" would be good here. Side to side, for and aft, rotational. A hitch in the giddyup, a pot that catches, or moves more freely? Lots of different diagnoses are possible with the information provided thus far. All we can do is guess at things, so far. It may be that you should be offering up a person in your area an adult beverage and/or some grilled pork or beef muscle to come over and listen to what you have going on. And it appears that there is something going on.
Or... it's really not that big of deal to remove the caliper, then check for noise. If still there, further dis-assembly would be required. I would strongly urge you to not take this to a dealer.
Iff'n you have a trailer, you could haul it down to Guy Young's(Connieklr on the other forum) garage, near Richmond VA(I think). Honest dude that won't rip you off. Or haul it down to SiSF's place outside of Tampa. Those are the only two people I can think of that I would want to pay to work on a C10 Connie. Oops, I would include MOB, Larry Buck, Brian Snowberg, and Dan Bergman on that list, also.