I'm using the volt gauge and a nice multimeter, they both give the same readings.
I've got a solid 13v with the AC and lights on, more like 13.6v with no load, which is good enough for now. I may try replacing the regulator.
get one of them fancy adjustable voltage regulators, more expensive up front but modern good quality batteries can charge to a higher voltage than the stock regulator can provide
Those Densos always go bad for some reason. I stick with the Bosch 100 amp alternators now and haven't looked back.
I want a 100a alternator but I don't want to mess with the stock 80a at this point. It hasn't let me down for a decade, besides a brush replacement