As a precaution against the headset adjustment becoming too tight, I recommend tightening a quill stem, by itself, into the steerer. With the quill in place, and the adjustment then secured, there will be no chance of the adjustment tightening up when the bars and stem are finally installed.
The stem by itself won't mask a slightly-tight adjustment the way that a complete cockpit setup can (cables are huge offenders). Removing the front wheel to give the assembly a final check before the real stem and bars are fitted will give a good read on just how much bearing pre-load actually exists.