Looking to upgrade my alternator, and eventually bypass the amp gauge. Other than that, I want to use the existing wiring/regulator. The regulator is a newer solid state version that looks stock. It's currently got the original round back/externally regulated version(one wire? it's got a wire running to the starter relay through the cabin, and one with a spade connector which I assume goes to the regulator. Is that considered one wire?)
Anyhoo... would the powermaster 80 amp alternator be too much for my wiring assuming I *don't* do the amp gauge bypass right away? If do, any other options? thanks!

You can run a newer dual field square back alternator with your current single field voltage regulator setup. Hook the voltage regualtor wire to one of the two field terminals on the alternator and ground the other alternator terminal and you are good to go.

I believe the 75 or 80 amp Powermaster is too much for stock wiring. Even 60 amps will cook it if the bulkhead connector is not well cleaned and greased. You would be running up to 80 amps through 12 guage wire and a 3/8" spade connector at the bulkhead. With the goal of keeping it simple and cost low two suggestions.

One would be to get a reman 60 amp square back alternator from the parts store or other source and thoroughly clean and grease the bulkhead connector terminals. Also clean and tighten the ammeter connection studs.

The other suggestion is to get the 75/80 amp Powermaster unit and add another charge wire from the alternator stud to the fender relay. For this application, 10 guage wire with a short length of 14 guage fusible link added would be plenty. The added charge wire would effectivly bypass the ammeter and greatly reduce load on the bulkhead connector. With this modification the ammeter wouldn't work and you would need to add an aftermarket volt meter hooked to a key switched power source to monitor system condition.

that is what I did, took the square back from an 89 full size chrysler. puts out 74 amps. more than enough, and only 50 bucks with lifetime warranty compared to power master.

just ground one of the fields on the alt and your old vr works fine.

Actually the size of the alt and wiring dont really come into play much.The big thing is the draw on the alt.If you have little draw factory wiring is sufficent.Now if you have lots of draw such as big stereo,elec pump,elec fan the wiring needs upgraded.By passing the amp gauge is a good thing though.I run a 78 amp in the 65 full factory wiring.I have basically nothing for a draw though.Rocky

Thanks all, I guess the amp guage bypass is the best thing to do. I have very little draw as well, but the lights still dim with nothing else turned on. If I use a newer square back alt, does it matter which of the field terminals goes to ground? Or just pick one? Thanks for all the good info!

just pick one.