anyone know stock '68 alternator amp output

well, many people me included, have had the mechanical VRs stick on, and overcharge the battery, and start blowing light bulbs. But mostly the set points are too low. The headlamps end up being very dim, and the battery suffers from chronic undercharge.. They also seem to be temperature sensitive.

The electronic VRs solve all those issues. You can, or used to be able to, retrofit a VR designed for the old single fields. IDK if they are still available. You can retrofit an isolated field 70up alt into an older chassis by grounding the one extra brush terminal. But you,normally, would not try to fit an older alt into a 70up chassis.
The new VRs control the ground circuit to the field, varying the field strength to affect the charging. The older mechanicals varied the field strength on the power side. The alternator doesn't care which side is regulated, but the VRs sure do. The electronic VRs seem to last for decades. The alternators too, just requiring occasional bearings and brushes, all very cheap parts. The front bearing needs a special puller to replace, but the puller is cheaper than a rebuilt alternator! Go figure! The rest of the alternator parts are practically engineered to last ,oh let's see I think mine is a 70's model,actually,so 50 years on the same armature and field coil. OOps I think I replaced the field once,not sure exactly,lol, which car that was in. It mighta been in my 73 Swinger. Hyup, time marches on........Actually, this current alt may be the same one that was in my 73,heehee. In which case it has been in nearly continuous use since new. WOW!