Well--I'm not quite sure that I understand you but what's really important is the distance from the nut to the twelfth fret is the same as the distance from the twelfth fret to the bridge. As as you make sure those distances equal to eachother, you can build a neck of pretty much any scale lenth to work w/ your body and bridge placement. There's no "universal" though in practice things tend to be built to certain popular specs--Fender, Gibson, PRS, etc.