if you've heard horror stories about N gennies.. stop listening to those people.. they are full of it.
ford 8n and naa and 00/01 gennies are very robust.
it uses a mechanical voltage regulator. it changes field current based on charge voltage ( and load ).
static.. a charged 6v bat should be around 6.3vdc
running at high idle, after a few minutes, voltage should be around 7.2 or so.
many consumer grade volt meters don't like the ignition and brush noise from a breaker contact system.. thus if your meter has a slow sample rate.. it may display eratic results if it is a digital anyway. analog are much less sensitive to the noise issue.