So, I recently, out of boredom, decided to upgrade my headset from a beaten up Shimano 600 to a sparkly NOS Dura Ace that I got for cheap on eBay. Anyway, I didn't think there'd be any significant difference in stack height, but there is. I think the Dura Ace is about 4 or 5 more mm than the 600. I know that the locking ring isn't really necessary, so I'm not worried about that, but what I am worried about, is the fact that there's maybe 2-3mm of thread for the headset, I can turn the top nut maybe 2.5 times. If I put Loc-Tite on there, will that be enough, or should I just give up the ghost and put the 600 back on?

Thanks for all your help!