There are two kinds of voltage regulators- - - -Delco-Remy, and "WRONG"! If you're buying a new regulator, you're taking a huge gamble. A lot of them are bad right out of the box, due to the fact they're made in some offshore sweatshop by virtual slave labor. The quality control is just about nonexistent. There are plenty of serviceable "pre-owned" Delco units on Ebay. The prices aren't outrageous, either. A little primer and paint will make them look brand new. Then all you'll need to do is find someone who knows how to adjust it to get the proper output from the generator. The adjustments are:
Closing voltage
Current regulator
Voltage regulator
The adjustments are made by changing the spring tension on each of the three sets of magnetic points under the cover. The voltage regulator needs to be adjusted when the generator is charging against a fully charged battery. On a 6V system, the setting needs to be 7.5 V, on a 12V it's 14.5V. Adjustments tend to reduce a little when the cover is installed, due to better magnetic conduction of the stamped steel.
Jerry