I've tried two different brands of HO alternators without much success. Neither were/are very good quality, in my opinion.
I'm looking for a good alternator, NOT cheap. At least 100 real amps at a realistic idle speed.
I did put a small pulley on one alternator. The small pulley helped the amps at idle, but the alternator only lasted about two years. I don't put a lot of miles on the vehicle. I'm sure the small pulley must have shortened the lifespan of the alternator.