Interesting reply over on the SOHC forum
"My opinion: that is a shunt regulator and not the ideal choice for your bike. These run the alternator at 100% power 100% of the time and almost all waste excess power to ground. Not a worrying horsepower stealer, full alternator load takes maybe 1/3 horsepower from the engine. But the alternator wasn't designed for full zot all the time, and may overheat.
This type of regulator is normal on permanent magnet alternator bikes.
A field control regulator varying alternator output according to load is what it was designed for, there are several aftermarket ones available.
To use this one, the black wire from your reg/rect has to be connected to the black and white wires on the original regulator. You take those wires off the regulator and plug in the spades on the new one. If any metal shows at those connections, tape over them: the connector metal must not contact the frame or anything metal attached to the frame. The green wire from the old regulator can be left loose."