Stop in for a cup of coffee

I haven't attempted than one so don't know. all my experience in A-bodies.
Volt gauge would show the same as current changes.
The big difference in the 2 gauge types is in how they are wired into the electrical system. Amp gauge measures current passing through it. So logically, All of the current has to pass through it for it to work, Thus requiring very large gauge wires. Its a lot of juice that could be and has been a serious fault in a very few cases ( considering the vast numbers produced and still in use today).
A volts gauge is simply tapped into the system with much smaller wiring, more or less sensing the current. A volt gauge failure cannot stop the entire car no more than temp' gauge failure can stop water flow. Amp gauge failure stops all electrical.
Curiosity is going to kill me. I just checked the '73 Dodge FSM. Ammeters for all. B-bodies with optional 65 amp alternator connect wires to the ammeter through a grommet. The alternator side goes back out through that grommet to a single post terminal block. I kindof like it.