pine floors 2
confirm this with the people you purchased the wood from,(they may be aware of some special condition with the wood)
I have never installed wood flooring at 6%. It should be with in a couple percent of the other woods in the building. Trim woods should be dried at the manufacturer/mill to about 6-7% but if I installed it that dry,there would definitely be problems because we have a humid climate here. I recommend stacking the flooring in the area to be it's home with air circulation around it for two weeks prior to installation to let it adjust. 11% is more common here. IO don't know where this will be going but unless it is in Arizona or a similar climate, 6% is the very bottom of the range. Setting a stipulation like that will make it nearly impossible to install in most places.
That said, I have worked with a lot of Anitque Heart Pine. If that is truely what is under discussion here, it is one of the most stable woods I know of, and there is little to worry about.
I agree that it should be nailed and not glued though, in most circumstances.