PropFlux, Now that you have the system up and running you must check to see if you have any voltage drop at 2 points while under load.
1) Between the positive lead of the voltage regulator connector and the positive battery post.
2) Between the negative lead of the voltage regulator connector and the Negative battery post.
Add those two numbers together. They better not equal .5 volts or you will continue to eat stators/regulators alive.
Since you have gone through 3 regulators in 20K miles, it tells me you have a hidden problem.