The one wire systems are often restricted in ability to start charging unless spooled to about 2500RPM. Near wide open on a farm tractor with over driven speed on the pulleys is necessary.
If you have it wired through the existing regulator Bat and Gen wires, and they are good, it will work that way. If you have additional wires that connect to the ignition from the #1 terminal on the (one wire) alternator, you are probably messing with the already modified regulator. I would not do that. I would only have that one wire from the alt to the (correct) side of the amp meter.
I only install the 3 wire systems. They do not stay in a pilot draw (current draining) mode when off, and they start charging just as a car does at first rotation.
The link is what I would do. using a stock 10SI.
The bypass wire from the starter to the ballast resistor needs to have a diode in it if you use it. That diode (in addition to the one shown) prevents the starter from being in the ignition circuit. The ignition circuit cannot handle turning the starter. Jim