Ok...The amp output of the alternator will have no damaging affect on your original wiring if it is in good condtion. The amp rating is the maximum amount of amps you can expect out of the alternator, but the regulator will regulate the amount of current you need based on your electrical load. Now because your original system used about 36 amps for everything a 60 amp alternator will be more than big enough to do what you need to do.
Keep in mind that one-wire alternators are self exciting which means that it takes about 1200 rpms engine speed to excite the alternator and make it begin charging, and in a lot of cases it will drop out and stop charging if the speed is to low. That voltage surge is hard on bulbs and electrical accessories. One-wire alternators were originally designed for racing applications were idle speeds were well past 1200 rpms and the electrical load was minimal usually just ignition and a few accessories.
By contrast a two wire alternator uses a small amount of battery current to excite the alternator when the ignition key is turned on. That way you will have a constant output regardless of idle speeds. This is how all modern trucks are wired. This system works best because you have the same alternator output at idle and low rpms.
One final word about 6 volt alternators. Ask what the actual output is at 6 volts. Many 6-volt alternators are built by putting a 6 volt regulator inside of a 12 volt alternator. When this happens the voltage output is reduced by half AND the amperage output is also reduced by half. So if you start out with a 60 amp alternator, with the 6-volt regulator installed you will end up with a 30 amp 6-volt. You also need to keep in mind that any alternator will only provide about 1/2 of its rated output at idle so that leaves you with a 15 amp alternator at idle, and you need an about 25 amps top run ignition and headlights etc.
Your best bet is to buy a two wire 6 volt alternator that is built from scratch as a true 6-volt alternator. They cost more to build because they use a speciality wound rotor and stator but the end result is a true 60 amp 6 volt alternator. As the old saying goes you get what you pay for. Because we all like electrical so well it usually pays to spend a little more money and get it right the first time. Thanks Randy
